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Modern computers can do billions of calculations in a second. Being able to calculate many times per second allows modern computers to multi-task, which means they can do many different tasks at the same time. Computers do many different jobs where automation is useful. Some examples are controlling traffic lights, vehicles, security systems, washing machines and digital televisions. Computers can be designed to do almost anything with information. Computers are used to control large and small machines that, in the past, were controlled by humans. Most people have a personal computer at home or at work. They are used for things such as calculation, listening to music, reading an article, writing, or playing games.

Hardware Modern computers are electronic computer hardware. They do mathematical arithmetic very quickly, but computers do not really "think." They only follow the instructions in their software programs. The software uses the hardware when the user gives it instructions and produces useful outputs. Controls Computers are controlled with user interfaces. Input devices which include keyboards, computer mice, buttons, and touch screens, etc. Programs Computer programs are designed or written by computer programmers. A few programmers write programs in the computer's own language, called machine code. Most programs are written using a programming language like C, C++, JavaScript. These programming languages are more like the language with which one talks and writes every day. The compiler converts the user's instructions into binary code (machine code) that the computer will understand and do what is needed. History of computers

First computer In 1837, Charles Babbage proposed the first general mechanical computer, the Analytical Engine. The Analytical Engine contained an Arithmetic Logic Unit, basic flow control, punched cards, and integrated memory. It is the first general-purpose computer concept that could be used for many things and not only one particular computation. However, this computer was never built while Charles Babbage was alive, because he didn't have enough money. In 1910, Henry Babbage, Charles Babbage's youngest son, was able to complete a portion of this machine and perform basic calculations.

Before the computer era there were machines that could do the same thing over and over again, like a music box. But some people wanted to be able to tell their machine to do different things. For example, they wanted to tell the music box to play different music every time. This part of computer history is called the "history of programmable machines" which in simple words means "the history of machines that I can order to do different things if I know how to speak their language."

One of the first examples of this was built by Hero of Alexandria (c. 10–70 AD). He built a mechanical theater which performed a play lasting 10 minutes and was operated by a complex system of ropes and drums. These ropes and drums were the language of the machine- they told what the machine did and when. Some people argue that this is the first programmable machine. Some people disagree on which early computer is programmable. Many say the "castle clock", an astronomical clock invented by Al-Jazari in 1206, is the first known programmable analog computer. The length of day and night could be adjusted every day in order to account for the changing lengths of day and night throughout the year. Some count this daily adjustment as computer programming. Others say the first computer was made by Charles Babbage. Ada Lovelace is considered to be the first programmer.

The computing era At the end of the Middle Ages, people started thinking math and engineering were more important. In 1623, Wilhelm Schickard made a mechanical calculator. Other Europeans made more calculators after him. They were not modern computers because they could only add, subtract, and multiply- you could not change what they did to make them do something like play Tetris. Because of this, we say they were not programmable. Now engineers use computers to design and plan.

In 1801, Joseph Marie Jacquard used punched paper cards to tell his textile loom what kind of pattern to weave. He could use punch cards to tell the loom what to do, and he could change the punch cards, which means he could program the loom to weave the pattern he wanted. This means the loom was programmable. At the end of the 1800s Herman Hollerith invented the recording of data on a medium that could then be read by a machine, developing punched card data processing technology for the 1890 U.S. census. His tabulating machines read and summarized data stored on punched cards and they began use for government and commercial data processing. Charles Babbage wanted to make a similar machine that could calculate. He called it "The Analytical Engine". Because Babbage did not have enough money and always changed his design when he had a better idea, he never built his Analytical Engine.

As time went on, computers were used more. People get bored easily doing the same thing over and over. Imagine spending your life writing things down on index cards, storing them, and then having to go find them again. The U.S. Census Bureau in 1890 had hundreds of people doing just that. It was expensive, and reports took a long time. Then an engineer worked out how to make machines do a lot of the work. Herman Hollerith invented a tabulating machine that would automatically add up information that the Census bureau collected. The Computing Tabulating Recording Corporation (which later became IBM) made his machines. They leased the machines instead of selling them. Makers of machines had long helped their users understand and repair them, and CTR's tech support was especially good. Because of machines like this, new ways of talking to these machines were invented, and new types of machines were invented, and eventually the computer as we know it was born.

Analog and digital computers In the first half of the 20th century, scientists started using computers, mostly because scientists had a lot of math to figure out and wanted to spend more of their time thinking about science questions instead of spending hours adding numbers together. For example, if they had to launch a rocket ship, they needed to do a lot of math to make sure the rocket worked right. So they put together computers. These analog computers used analog circuits, which made them very hard to program. In the 1930s, they invented digital computers, and soon made them easier to program. However this is not the case as many consecutive attempts have been made to bring arithmetic logic to l3.Analog computers are mechanical or electronic devices which solve problems.Some are used to control machines as well.

High-scale computers Scientists figured out how to make and use digital computers in the 1930s to 1940s. Scientists made a lot of digital computers, and as they did, they figured out how to ask them the right sorts of questions to get the most out of them. Here are a few of the computers they built:

Konrad Zuse's electromechanical "Z machines". The Z3 (1941) was the first working machine that used binary arithmetic. Binary arithmetic means using "Yes" and "No." to add numbers together. You could also program it. In 1998 the Z3 was proved to be Turing complete. Turing complete means that it is possible to tell this particular computer anything that it is mathematically possible to tell a computer. It is the world's first modern computer. The non-programmable Atanasoff–Berry Computer (1941) which used vacuum tubes to store "yes" and "no" answers, and regenerative capacitor memory. The Harvard Mark I (1944), A big computer that you could kind of program. The U.S. Army's Ballistics Research Laboratory ENIAC (1946), which could add numbers the way people do (using the numbers 0 through 9) and is sometimes called the first general purpose electronic computer (since Konrad Zuse's Z3 of 1941 used electromagnets instead of electronics). At first, however, the only way to reprogram ENIAC was by rewiring it.

Several developers of ENIAC saw its problems. They invented a way to for a computer to remember what they had told it, and a way to change what it remembered. This is known as "stored program architecture" or von Neumann architecture. John von Neumann talked about this design in the paper First Draft of a Report on the EDVAC, distributed in 1945. A number of projects to develop computers based on the stored-program architecture started around this time. The first of these was completed in Great Britain. The first to be demonstrated working was the Manchester Small-Scale Experimental Machine (SSEM or "Baby"), while the EDSAC, completed a year after SSEM, was the first really useful computer that used the stored program design. Shortly afterwards, the machine originally described by von Neumann's paper—EDVAC—was completed but was not ready for two years.

Nearly all modern computers use the stored-program architecture. It has become the main concept which defines a modern computer. The technologies used to build computers have changed since the 1940s, but many current computers still use the von-Neumann architecture. In the 1950s computers were built out of mostly vacuum tubes. Transistors replaced vacuum tubes in the 1960s because they were smaller and cheaper. They also need less power and do not break down as much as vacuum tubes. In the 1970s, technologies were based on integrated circuits. Microprocessors, such as the Intel 4004 made computers smaller, cheaper, faster and more reliable. By the 1980s, microcontrollers became small and cheap enough to replace mechanical controls in things like washing machines. The 1980s also saw home computers and personal computers. With the evolution of the Internet, personal computers are becoming as common as the television and the telephone in the household.

In 2005 Nokia started to call some of its mobile phones (the N-series) "multimedia computers" and after the launch of the Apple iPhone in 2007, many are now starting to add the smartphone category among "real" computers. In 2008, if smartphones are included in the numbers of computers in the world, the biggest computer maker by units sold, was no longer Hewlett-Packard, but rather Nokia. Kinds of computers There are many types of computers. Some include: personal computer workstation mainframe minicomputer supercomputer embedded system tablet computer quantum computers

A "desktop computer" is a small machine that has a screen (which is not part of the computer). Most people keep them on top of a desk, which is why they are called "desktop computers." "Laptop computers" are computers small enough to fit on your lap. This makes them easy to carry around. Both laptops and desktops are called personal computers, because one person at a time uses them for things like playing music, surfing the web, or playing video games.

There are larger computers that can be used by multiple people at the same time. These are called "mainframes," and these computers do all the things that make things like the internet work. You can think of a personal computer like this: the personal computer is like your skin: you can see it, other people can see it, and through your skin you feel wind, water, air, and the rest of the world. A mainframe is more like your internal organs: you never see them, and you barely even think about them, but if they suddenly went missing, you would have some very big problems.

An embedded computer, also called an embedded system is a computer that does one thing and one thing only, and usually does it very well. For example, an alarm clock is an embedded computer. It tells the time. Unlike your personal computer, you cannot use your clock to play Tetris. Because of this, we say that embedded computers cannot be programmed because you cannot install more programs on your clock. Some mobile phones, automatic teller machines, microwave ovens, CD players and cars are operated by embedded computers. All-in-one PC All-in-one computers are desktop computers that have all of the computer's inner mechanisms in the same case as the monitor. Apple has made several popular examples of all-in-one computers, such as the original Macintosh of the mid-1980s and the iMac of the late 1990s and 2000s. Uses of computers

Uses of computers At home Playing computer games Writing Solving math problems Watching videos Listening to music and audio Audio, Video and photo editing Creating sound or video Communicating with other people Using The Internet Online shopping Drawing Online bill payments Online business At work Word processing Spreadsheets Presentations Photo Editing E-mail Video editing/rendering/encoding Audio recording System Management Website Development Software Development

Working methods Computers store data and the instructions as numbers, because computers can do things with numbers very quickly. These data are stored as binary symbols (1s and 0s). A 1 or a 0 symbol stored by a computer is called a bit, which comes from the words binary digit. Computers can use many bits together to represent instructions and the data that these instructions use. A list of instructions is called a program and is stored on the computer's hard disk. Computers work through the program by using a central processing unit, and they use fast memory called RAM (also known as Random Access Memory) as a space to store the instructions and data while they are doing this. When the computer wants to store the results of the program for later, it uses the hard disk because things stored on a hard disk can still be remembered after the computer is turned off.

An operating system tells the computer how to understand what jobs it has to do, how to do these jobs, and how to tell people the results. Millions of computers may be using the same operating system, while each computer can have its own application programs to do what its user needs. Using the same operating systems makes it easy to learn how to use computers for new things. A user who needs to use a computer for something different, can learn how to use a new application program. Some operating systems can have simple command lines or a fully user-friendly GUI.

The Internet One of the most important jobs that computers do for people is helping with communication. Communication is how people share information. Computers have helped people move forward in science, medicine, business, and learning, because they let experts from anywhere in the world work with each other and share information. They also let other people communicate with each other, do their jobs almost anywhere, learn about almost anything, or share their opinions with each other. The Internet is the thing that lets people communicate between their computers. The Internet also allows the computer user to play an Online game. Computers and waste A computer is now almost always an electronic device. It usually contains materials that will become electronic waste when discarded. When a new computer is bought in some places, laws require that the cost of its waste management must also be paid for. This is called product stewardship.

Computers can become obsolete quickly, depending on what programs the user runs. Very often, they are thrown away within two or three years, because some newer programs require a more powerful computer. This makes the problem worse, so computer recycling happens a lot. Many projects try to send working computers to developing nations so they can be re-used and will not become waste as quickly, as most people do not need to run new programs. Some computer parts, such as hard drives, can break easily. When these parts end up in the landfill, they can put poisonous chemicals like lead into the ground-water. Hard drives can also contain secret information like credit card numbers. If the hard drive is not erased before being thrown away, an identity thief can get the information from the hard drive, even if the drive doesn't work, and use it to steal money from the previous owner's bank account.

Main hardware Computers come in different forms, but most of them have a common design. All computers have a CPU. All computers have some kind of data bus which lets them get inputs or output things to the environment. All computers have some form of memory. These are usually chips (integrated circuits) which can hold information. Many computers have some kind of sensors, which lets them get input from their environment. Many computers have some kind of display device, which lets them show output. They may also have other peripheral devices connected.

A computer has several main parts. When comparing a computer to a human body, the CPU is like a brain. It does most of the thinking and tells the rest of the computer how to work. The CPU is on the Motherboard, which is like the skeleton. It provides the basis for where the other parts go, and carries the nerves that connect them to each other and the CPU. The motherboard is connected to a power supply, which provides electricity to the entire computer. The various drives (CD drive, floppy drive, and on many newer computers, USB flash drive) act like eyes, ears, and fingers, and allow the computer to read different types of storage, in the same way that a human can read different types of books. The hard drive is like a human's memory, and keeps track of all the data stored on the computer. Most computers have a sound card or another method of making sound, which is like vocal cords, or a voice box. Connected to the sound card are speakers, which are like a mouth, and are where the sound comes out

. Computers might also have a graphics card, which helps the computer to create visual effects, such as 3D environments, or more realistic colors, and more powerful graphics cards can make more realistic or more advanced images, in the same way a well trained artist can.

Largest computer companies References

Chinese might mean: Anything related to the country of China Chinese people, the people of China Chinese language Chinese characters, the symbols used to write the Chinese and Japanese languages

A continent is a large area of the land on Earth that is joined. There are no strict rules for what land is considered a continent, but in general it is agreed there are six or seven continents in the world, including Africa, Antarctica, Asia, Europe, North America, Oceania (or Australasia), and South America. Statistics The most populous continent by population is Asia, followed by Africa. The third most populous continent is Europe. The fourth most populous is North America, and then South America. In sub-Saharan Africa, the largest age group are denarians (in their teens). In north Africa, the largest age group are vicenarian (in their twenties). In Europe, most people are tricenarian (in their thirties) or quadragenarian (in their forties).

Continents Geologists use the term continent to mean continental crust, a platform of metamorphic and igneous rock, largely of granitic composition. Continental crust is less dense and much thicker than oceanic crust, which is why it "floats" higher than oceanic crust on the underlying mantle. This explains why the continents form high platforms surrounded by deep ocean basins. Australia Some sources say that Australia is one of the seven continents. Others say that Australia is part of a larger continent, such as Australasia, or Oceania. Oceania is a region which includes Australia, New Zealand and the Pacific Islands. Australasia includes at least all countries on the Australian continental plate. This includes the islands of New Guinea, Tasmania, New Zealand and a number of smaller islands. It is on the south-eastern side of the Wallace Line, with distinct differences in its biology from the Asian side of the line.

"It includes all the islands of the Malay Archipelago... as well as the various groups of islands in the Pacific. The term has been used in very different senses". Zealandia Zealandia is an almost entirely submerged land mass, and 93% of it still remains under water. Zealandia may have broken off the Australian plate between 85 and 130 million years ago. North and South America North America and South America together are often described as one continent, "the Americas", or simply "America". This has the advantage of including Central America and the Caribbean islands. Otherwise, Central America is counted as part of North America.

Eurasia Eurasia is not really an alternative, rather it is a recognition that the landmasses of Europe and Asia are continuous, and some of its largest countries are in both regions. Russia extends from eastern Europe to the far east of Asia without a break. The Ural Mountains, which run roughly north–south, are the traditional dividing-line between Europe and Asia. For many purposes it is convenient to consider the great landmass as a single continent, Eurasia. When British people talk about "the Continent" (or "Continental" things) they mean the European mainland. This meaning is not used as much as it used to be, but is still seen in phrases like "Continental breakfast" (rolls with cheese, jam etc. as distinct from an "English breakfast" which is a cooked breakfast).

Continents not only move but also sometimes move against each other. The Indian subcontinent has been colliding with the Eurasian continent for a while now. As these continents push against each other, they buckle and bend. Because of this, the Himalaya Mountains, with Mount Everest, are still being built up today. Antarctica Antarctica is Earth's fifth largest continent. Antarctica, the coldest place on Earth, covers Earth's South Pole. It has a surface area of ~13.6 –14 million km2: this is about 1.4 times the size of Europe, The continent only has two seasons, a brief summer and a long winter. Antarctica is a cold desert. It does not rain or snow much there. Ever since its discovery in 1812, Antarctica was a great challenge for explorers. Despite being nearly completely covered by a thick layer of ice, Antarctica has a range of aquatic and terrestrial environments.

Origin of continents A craton is an old and stable part of the continental lithosphere. It is the Earth's two topmost layers, the crust and the uppermost mantle. There are various hypotheses of how cratons have been formed.. Continents may have been formed by giant meteorite impacts in the first billion years of Earth's existence. The question is not yet settled. What is clear is that the cratons are very old, and are the basis for the continents we see today. Related pages List of countries by continents References Geology

The Greek classical elements are fire, air, water, and earth. In Greek philosophy, science and medicine, these make up a whole. Fire is both hot and dry. Air is both hot and wet. Water is both cold and wet. Earth is both cold and dry. The image below has two squares on top of each other. The corners of one are the classical elements. The corners of the other are the properties. Galen said these elements were used by Hippocrates to describe the human body. The elements are linked to the four humours: phlegm (water), yellow bile (fire), black bile (earth), and blood (air). In Chinese Taoism the elements are metal, wood, water, fire, earth (). References Ancient Greece History of science

China ( Pinyin: Zhōngguó) is a cultural region, an ancient civilization, and a nation in East Asia. The official name is People's Republic of China or PRC. The last Chinese Civil War (19271949) resulted in two different political powers today: The Republic of China (ROC) (since 1911), commonly known as China since 1 January, 1911 to 25 October, 1971. Now commonly known as Taiwan, has control over the islands of Taiwan, Penghu, Kinmen, and Matsu. The People's Republic of China (PRC) (since 1949), commonly known as China, has control over mainland China and the largely self-governing territories of Hong Kong (since 1997) and Macau (since 1999).

China is one of the world's oldest civilizations: it has the oldest continuous civilization near the Yellow River region. There is archaeological evidence over 5,000 years old. China also has one of the world's oldest writing systems (and the oldest in use today). China has been the source of many major inventions. Geographically, China’s longest river is the Yangtze River which runs through mega cities and is home to many species. It is the world’s third longest river. Origins The first recorded use of the word "China" is dated 1555. It is derived from chīnī, a Persian adjective meaning 'Chinese' which was popularized in Europe by Marco Polo. History

History Ancient (2100 B.C. 1500 A.D.) Ancient China was one of the first civilizations and was active since the 2nd millennium BC as a feudal society. Chinese civilization was also one of the few to invent writing, with the others being Mesopotamia, the Indus Valley civilization, the Maya civilization, the Minoan civilization of ancient Greece, and Ancient Egypt. It reached its golden age during the Tang Dynasty (c. A.D. 10th century). Home of Confucianism and Daoism, it had great influence on nearby countries including Japan, Korea, and Vietnam in the areas of political system, philosophy, religion, art, writing and literature. China is home to some of the oldest artwork in the world. Statues and pottery, as well as decorations made of jade, are some classic examples.

Before the Qin Dynasty united China, there were many small feudal states, nominally loyal to the Zhou King, that fought each other for hundreds of years in a war to control China. The majority of these states were ruled by relatives and clansmen of the Zhou royal house and carried the surname Ji (姬) and so were tied by family bonds to the Zhou king, to whom they were ritually subordinate, as members of collateral or lesser lineages. A minority of these states, such as the Qin and Chu, were ruled by non-Zhou clansmen, and were awarded their fiefs on account of some merit. Over time, these feudal states attained to power and wealth, that exceeded that of their Zhou nominal overlord, whose direct authority became confined to a very small territory near present-day Zhengzhou. These states also began to acquire some distinctive characteristics and identities of their own during the long centuries of loose control by the Zhou

. Eventually, the Zhou kings were eclipsed in power by two especially problematic vassals - the Qin and Chu, and the functional independence of the Qin later led to its gradual conquest of all other vassal states and the formal supplantation of the Zhou to form a heavily centralised Empire.

The long decline of the Zhou, incidentally the longest ruling dynastic house of China, is known as the Warring States Period. Despite the bloodiness and strife of the period, this was the time when many great philosophies emerged - including Confucianism and Daoism as a response to disintegrating central authority of the Zhou kings and fluctuating power of the vassal states, and the general uncertainty of that era. Confucianism and Daoism have been the foundation of many social values seen in modern east Asian cultures today. Other notable dynasties include the Han (from which is derived the ethnonym the Han Chinese, which is synonymous with the older self-referential term - the Huaxia) as well as dynasties such as the Tang, Song, and Ming, which were characterised by periods of affluence, wealth, population growth, and the proliferation of literature.

During the later years, China was often raided or invaded by northern nomadic people such as the Xiongnu, the Xianbei, the Jurchens and the Mongols (the latter led by Genghis Khan and Kublai Khan). One effect of regular nomadic invasion and the collapse of native dynasties was the massive migration of Han Chinese - especially the aristocratic elite and the literati, to sparsely populated frontier regions south of the Yangzi river such as Jiangsu, Zhejiang, Guangdong and Fujian. Several notable waves of Han Chinese immigration to Jiangsu, Zhejiang, Guangdong and Fujian took place during the collapse of the Jin, the Tang, and the Song. Some nomadic groups succeeded in conquering the whole territory of China, establishing dynasties such as the Yuan (Mongol) and Qing (Manchu). Each time, they also brought new elements into Chinese culture - for instance, military uniform, the qipao and the pigtail, the latter of which was deeply resented by the Han Chinese. A new age

A new age While China achieved many things in the First millennium and early 2nd millennium, it became an isolationist country in the 15th century C.E. This was because Spain found enormous silver in the new continent, which was the main currency (money) in China and Europe at the time, and China did not want to be bought by the foreigners. By the time of the Renaissance, European powers started to take over other countries in Asia. While China was never actually taken over, many European countries, such as Britain and France built spheres of influence in China. Since China had cut itself off from the world over the previous few centuries, by the Qing Dynasty, it had fallen behind other countries in technology, and was helpless to stop this from happening. This had become clear when it lost the Opium Wars to Britain in the 19th century.

Still influenced by Western sources, China faced internal strife. The Taiping Rebellion or Taiping War occurred in China from 1851 through 1864. The Taiping Rebellion was led by Hong Xiuquan from Guangdong. Hong Xiuquan was influenced by Christian missionaries and declared himself the brother of Jesus. Hong made his mission to bring down the Qing Dynasty. Gaining influence on the southern Chinese population, the Taiping Rebellion attracted tens of thousands of supporters. The Taiping regime successfully created a state within the Qing Empire with the capital at Nanjing. Hong called his new state the Taiping Tianguo or "The Heavenly State of Great Peace". Local armies eventually suppressed the rebellion at the final battle of Nanjing. In 1911, the Republic of China was founded after the Xinhai revolution led by Sun Yat-sen, but its government was very weak. Warlords controlled many areas. Chiang Kai-shek led wars against them, and he became president and dictator.

In 1931, Japan invaded Manchuria, a place in the northeastern part of China. On July 7, 1937, the Japanese attacked the rest of the country, starting what was called the Second Sino-Japanese War. On December 13 of that same year, The Japanese Army killed an estimated (guessed) 200,000 to 300,000 Chinese civilians (people) which is called Nanjing Massacre. The war later became part of World War II. The war was fought for eight years and millions of Chinese people were killed.

However, the Chinese Civil War later started between the Kuomintang (Nationalists) of the Republic of China (ROC) and the Communists of the People's Republic of China (PRC). The Communists wanted to make China like the Soviet Union, whereas the other side wanted to keep China in its current state at the time. The Communists were led by Mao Zedong, Liu Shaoqi, Zhou Enlai and others. The Communists eventually won the war by uniting all the people from different positions. The Nationalists (led by Chiang Kai-shek) fled to the island of Taiwan and set up their new capital city in Taipei. After the Chinese Civil War, the Communist leader Mao Zedong declared a new country, the People's Republic of China (PRC), in Beijing on October 1, 1949.

Under Mao the country stayed poor while Taiwan became richer. His attempt at industrialization and collectivization with the Great Leap Forward led to the deaths of many people from famine. The Cultural Revolution caused great social upheaval. After 1976, China underwent market economy reforms under Deng Xiaoping, and experienced rapid economic growth, which made the former progress made by Taiwan became overshadowed. China is now one of the largest economies in the world, relying mainly on exports and manufactering. In recent history, China has had problems with protests, blocking of information on the Internet, and censorship of news. 1989 was notable for the controversial Tiananmen Square protests. Since the 2008 Olympics, China has hosted many major international events, and the 2022 Winter Olympics were held in Beijing, China. Geography

Geography China's landscape is vast and diverse. It ranges from the Gobi and Taklamakan Deserts in the north to subtropical forests in the south. The Himalaya, Karakoram, Pamir and Tian Shan mountain ranges separate China from much of South and Central Asia. The Yangtze and Yellow Rivers run from the Tibetan Plateau to the densely populated eastern coast. The Yangtze River is the third-longest river in the world while the Yellow River is the sixth-longest. China's coastline along the Pacific Ocean is 14,500 kilometers (9,000 mi) long. It is bounded by the Bohai, Yellow, East China and South China seas. China connects through the Kazakh border to the Eurasian Steppe. The Eurasian Steppe has been an artery of communication between East and West since the Neolithic through the Steppe route. The Steppe Route is the ancestor of the terrestrial Silk Road(s). Politics

Politics China's constitution states that The People's Republic of China "is a socialist state under the people's democratic dictatorship led by the working class and based on the alliance of workers and peasants". It also states the state organs "apply the principle of democratic centralism." The PRC is one of the world's only socialist states openly being communist. Military With 2.3 million active troops, the People's Liberation Army (PLA) is the largest standing military force in the world. The PLA is commanded by the Central Military Commission (CMC). China has the second-biggest military reserve force, only behind North Korea. The PLA consists of the Ground Force (PLAGF), the Navy (PLAN), the Air Force (PLAAF), and the People's Liberation Army Rocket Force (PLARF). According to the Chinese government, China's military budget for 2017 was US$151,5 billion. China has the world's second-largest military budget. Science and technology

China was once a world leader in science and technology up until the Ming dynasty. There are many Ancient Chinese discoveries and inventions. For example, papermaking, printing, the compass, and gunpowder are known as the Four Great Inventions. They became widespread across East Asia, the Middle East and later to Europe. Chinese mathematicians were the first to use negative numbers. By the 17th century, Europe and the Western world became better than China in science and technology. Demographics The national census of 2010 recorded the population of the People's Republic of China to be about 1,370,536,875. About 16.60% of the population were 14 years old or younger, 70.14% were between 15 and 59 years old, and 13.26% were over 60 years old. The population growth rate for 2013 is estimated to be 0.46%.

Culture China is the origin of Eastern martial arts, called Kung Fu or its first name Wushu. China is also the home of the well-respected Spa Monastery and Wudang Mountains. Martial art started more for the purpose of survival, defense, and warfare than art. Over time some art forms have branched off, while others have retained their distinct Chinese flavor. China has had renowned artists including Wong Fei Hung (Huang Fei Hung or Hwang Fei Hung) and many others. Art has also co-existed with a variety of paints including the more standard 18 colors. Legendary and controversial moves like Big Mak are also praised and talked about within the culture. China has many traditional festivals, such as Spring Festival, Dragon Boat Festival, Mid-autumn Festival and so on. The most important is Chinese New Year. People in China will have holidays to celebrate these festivals. Festivals Spring Festival is the Chinese New Year.

Dragon Boat Festival is celebrated to commemorate the death of Qu Yuan, a patriotic poet of the State of Chu during the Warring States period. He persuaded his emperor not to accept Qin's diplomats' offers several times but his emperor did not listen to him. He was very sad and ended up jumping into the river to end his life. The people loved him so much that they did not want the fish to eat his corpse. They made and threw rice dumplings into the river. They hope the fish eat these dumplings instead of the poet's corpse. They also rowed dragon boats in the river to get rid of the fish. Such practices, eating rice dumplings and holding dragon boat races, become what Chinese do in this festival nowadays.

Held on the fifteenth day of the eighth lunar month, Mid-Autumn Festival is a festival for families. Now when the festival sets in, people would sit together to eat moon cakes, appreciate the bright full moon cakes, appreciate the bright full moon, celebrate the bumper harvest and enjoy the family love and happiness. To the Chinese people, the full moon symbolizes family reunion, as does the "moon cakes." Hence the Mid-Autumn Festival is also called the Family Reunion Festival. Notes References Other websites Map of China City Photo Gallery of China China | Geography | People | Economy China -Citizendium Divided regions Republics

A country is a distinct territory with defined borders, boundaries, people and government. Most countries are sovereign states while others make up one part of a larger state Every part of the world is in a country. The people that live in a country are referred to as a nation. The government that runs the country is called the state. Vatican City is the smallest country in the world and the largest is Russia. Number of countries There is no universally accepted answer as to how many countries in the world there actually are, however the minimum answer is 193 for the 193 United Nations members. This can be developed on even further by adding the constituent countries of the United Kingdom, The Kingdom of the Netherlands and the Kingdom of Denmark which could add anywhere from three to eleven morecountries. There are multiple organisations that have their own lists of countries, one example being the Travellers Century Club which recognises 330 countries as of January 2022.

Disputed countries Taiwan is classified as a country. However, there is an ongoing dispute over Taiwan's independence with the People's Republic of China. There are a number of disputed areas that have declared independence from their parent state and receive limited recognition. For example, Kosovo, Transnistria, Abkhazia, South Ossetia, Northern Cyprus, Artsakh and Somaliland. These are just some of the many examples of territories with limited to no recognition that are sometimes classed as countries. There is a lot of controversy surrounding the above examples and quite often any of these territories may be counted as countries purely based on opinion. If all of the above were added the list of U.N members there could be anything up to 211 countries. There are, however, many more territories with unique political circumstances that could also be counted.

Depending on how loosely the dictionary definition for the word country is used there could be many more than 193 countries in the world. The matter is purely subjective depending on varying opinions. Constituent country Constituent country is a term sometimes used, usually by official institutions, in contexts in which a number of countries are part of a sovereign state. The Organisation for Economic Co-operation and Development (OECD) has used the term referring to the former Yugoslavia, and the European institutions like the Council of Europe often use it in reference to the European Union. Territorial dispute

A disputed territory is that territory whose sovereignty is jealously desired by two or more countries. Usually the administration of the territory is carried out by one of the countries that claims sovereignty, while the other country does not recognize the sovereignty over the territory of the other country. This does not usually happen in land or sea areas on which none possesses effective control, such as Antarctica, or only partially. Related pages State Sovereign state Nation References Other websites Geography Trainer 1.3.5 - Educational game aimed at school children to teach world capitals Geography Trainer US States 1.1 game List of countries Geography Site Country Profiles - Based on the CIA World Factbook Basic English 850 words

Colchester is a city in the northern part of the English county of Essex. It has a population of 104,000 people. People believe that Colchester is the oldest Roman town in England. History Before Roman times, Colchester was Camulodunon. This is a Celtic name that came from Camulos. Camulos was the Celtic god of war. The Romans called Colchester Camulodunum (written "CAMVLODVNVM") and made it the capital of Roman Britain. Colchester was attacked and burnt by Boudicca in 61 AD. The Romans moved their capital of Britannia to Londinium (now London), but Camulodunum remained an important city until the fifth century, when the Saxons conquered the region. The Roman town of Camulodunum, officially known as Colonia Victricensis, reached its peak in the Second and Third centuries AD. It may have reached a population of 30,000 in those centuries, but when the Romans withdrew from Britannia in 410 AD it probably had fewer than 5,000 inhabitants.

The church at the Benedictine abbey of Saint John the Baptist was destroyed in 1539. This action was part of the dissolution of the monasteries by King Henry VIII. Only a gate remains, that people still go to visit. King Cunobelinus (or "Cunobelin") was from Colchester. Until 2022, Colchester was officially a town, not a city. On 5 September, Queen Elizabeth II signed letters patent to grant it city status. This was planned as part of her Platinum Jubilee celebrations. However, she died three days later. On 29 September, these letters were publicly released. Twin cities Colchester is twinned with the following cities: Imola, Italy Wetzlar, Germany Avignon, France Notes Bibliography B D'Ambrosio. "Roman Camulodunum". Universita' Statale di Genova (Genova University). Genova, 2007 Settlements in Essex Cities in England

Cartography is making maps. It is part of geography. How people make maps is always changing. In the past, maps were drawn by hand, but today most printed maps are made using computers and people usually see maps on computer screens. Someone who makes maps is called a cartographer. Making a map can be as simple as drawing a direction on a napkin, or as complicated as showing a whole country or world. Anyone can make a map, but cartographers spend their lives learning how to make better maps. For many centuries maps were usually carefully drawn onto paper or parchment. Now they are made on a computer which makes them look neater with accurate images. Maps are of two main types: General maps with a variety of features. Thematic maps with particular themes for specific audiences. General maps are produced in a series. Governments produce them in larger-scale and smaller-scale maps of great detail. Thematic maps are now very common. They are necessary to show spatial, cultural and social data. References

References Related pages Map projection Surveying Topography Geodesy History of science Topography Topology

A creator is a person who creates something. In some religions (Judaism, Christianity, Islam) God (or Allah meaning the God in Arabic) is the most important and original creator of the whole universe - including Man who is made "in his image" (see Genesis) to observe it and control it like God. The idea that anything that a person is creating, like an idea, can be owned as property comes from the ethical traditions and legal codes that came from these religions. In other traditions (Buddhism, Native American mythology) anyone has this potential for creating, and can become part of the greater creating of the universe. Stewardship of home, land and all of Earth is a test for participating in this, or just good sense. Related pages Creation myth Theology

Contact network may mean: Creative network Social network Power network

Chorizo is a pork (pig-meat) sausage which people first made in the Iberian Peninsula. It is made with large pieces of fatty pork, chili pepper and paprika. The special taste of this sausage comes from the mild Spanish paprika in it. In the western hemisphere, the Mexican and Caribbean types are better known. These types of chorizo are made with smaller pieces of pork and different seasonings and peppers are used. Cured smoked chorizo is edible and can be eaten without cooking. Fresh chorizo must be cooked before eating. It can be eaten by its self, or as part of meal. It can also be used in place of ground beef or pork.

Chorizo can be fresh. Also it can be dried. It can be spicy or not spicy depending on the recipe. There are many ways to eat chorizo. It can be sliced and eaten as a snack, or cooked. Dishes like stews, soups and rice dishes also use Chorizo. In Spain, chorizo is served as a small plate of food with drinks. In Latin America, chorizo is served with beans and eggs for breakfast. To make chorizo, the pork is cut into small pieces. Then it is mixed with spices and other ingredients. The mixture is then put into a casing. Casing is a thin, tube-like skin. Casing is made from the intestine of a pig. The chorizo is then left to dry for a few weeks. By doing this chorizo gets its special flavor and texture. There are many kinds of chorizo. Recipe of chorizo also different in different countries. In Spain, there are two main kinds of chorizo: chorizo de verdeo, and chorizo de cantimpalo. Chorizo de verdeo made with white wine and chorizo de cantimpalomade with red wine

. In Latin America, chorizo is made with a mixture of chili peppers and other spices. It makes chorizo spicy. There are a few different ways to cook with chorizo. One popular way is to slice the chorizo and fry it in a pan until it is crispy. It can then be added to dishes like soups, stews and rice dishes. Chorizo can also be grilled, which gives it a smoky flavor. It can be sliced and added to sandwiches or served as a topping on pizza. Chorizo is a tasty and versatile food that can be enjoyed in many different ways.

References Sausage

Creativity is the ability of a person or group to make something new and useful or valuable, or the process of making something new and useful or valuable. It happens in all areas of life - science, art, literature and music. As a personal ability it is very difficult to measure. The reason is that we don't understand the mental processes that help some people be more creative than others. Judging what is creative is also controversial. Some people say only things which are historically new are creative, while other people say that if it is new for the creator and the people around them, then it is also creativity.

Some think that creativity is an important thing that makes humans different from apes. Others recognize that even apes, other primates, other mammals and some birds adapt to survive by being creative (for example - primates using tools). Liane Gabora believes that all culture comes from creativity, not imitation. Therefore, these people say, human science should focus on it (pay special attention to it): Ethics for example would focus on finding creative solutions to ethical dilemmas. Politics would focus on the political virtues that need some creativity. Imitation would not be the focus of education. Linguistics might be more interested in how new words are created by culture, rather than in how existing ones are used in grammar.

Intellectual interests (recognized as intellectual rights or intellectual property in the law) are a way to reward creativity in law, but they do not always work very well. A good example is copyright which is supposed to pay writers and artists, but may only pay lawyers to make (imitative) arguments in court. Creativity is a central question in economics, where it is known as ingenuity (the ability to come up with new ideas) or individual capital - capacities that individuals have, that do not arise from simple imitation of what is known already. This is separate from the instructional capital that might try to capture some of that in a patent or training system that helps others do what the individual leader or founder of the system can do. In urban economics there are various ways to measure creativity - the Bohemian Index and Gay Index are two attempts to do this accurately and predict the economic growth of cities based on creativity. Related pages Art Imagination Innovation Human behavior

The Cathar faith was a version of Christianity. They were usually considered Gnostics. The word 'Cathar' comes the Greek word katharos meaning 'unpolluted' (from Tobias Churton, The Gnostics) or "the pure ones". Principles The Cathars believed that the world had been made by a bad god. They believed that this bad god had taken them from the good god and put them in the world, but inside their bodies there was a spirit, and that spirit needed to return to the good god. They were famous for a belief in a form of reincarnation and believed that when someone died the bad god would put that person's spirit in a new body. They believed this cycle of coming back to life could be escaped by a ritual cleansing. They were opposed to the doctrine of sin.

Women were prominent in the faith. They were pacifists. They didn't eat anything that was made from other animals, including meat and cows milk. The only exception to this was fish. Fish was OK to eat because they believed fishes were not alive but just things that were sometimes produced from dirt and water. They preached tolerance of other faiths. They rejected the usual Christian rules of marriage and only believed in the New Testament. An earlier 10th-century Bulgarian heresy, Bogomilism and also Manichaeism started some of these trends. Language They used a bible in the language people spoke. Many other Christians used a Bible in Latin. Latin was spoken only by the priests.

Problems In 1145, open challenge to Catholic dominance began. In about 1165, the first Cathars said that the Church was "full of ravening (starving) wolves and hypocrites" and "worshipping the wrong God", right in front of the most powerful Catholics. In 1166, the Council of Oxford in England wiped out the English Cathars. It was also suppressed in Northern France. In 1167, Cathar bishops met to discuss organizing a counter Church - in the South of France, the Languedoc nobles protected it, and many noble women became "Perfects". Parish clergy had low morale, or confidence. Reactions The Catholic Church was against Catharism, seeing it as a heresy.

In the South of France there was tremendous religious fervor, and an economy that was starting to grow, and a social class of merchants and peasants was starting to grow. Peasants owned their own land. Meanwhile, in other parts of Europe, peasants were forced to give up their land to nobles and become serfs or slaves - the system of feudalism. There was a strong central absolute monarchy that did not exist in the South of France. The burghers and bankers had more power in this looser system. R. I. Moore is a historian who believes that it was desire to crush this system and take over the land that drove the attack.

However, there was real cultural and religious difference to cause problems: Troubadors, who combined some of the traditions of the Bards of the Celts, and Jews, were both part of the multicultural society in the South of France. Their influences were not appreciated by local or Roman Church figures. The 12th century Roman Catholic Monks were founding their monasteries outside the towns, drawing the best people there. Results The Cathars thus had little competition. The Cathar "Perfects", the so-called Good Men or Good Women, lived restrained lives and spread their faith in towns - where the Catholics in general did not have their best agents. Also, Cathars preached that only these Good leaders had to follow the regimens their whole lives - lay people could repent only on their deathbeds. Many 20th century Christian sects have similar beliefs. The Albigensian Crusade

Methods The Pope ordered a crusade against the Cathars in southern France. He said any crusader who answered the call would be given the same rewards as a crusader who went to the Holy Land. This was an absolution of all sin. In the Launguedoc, on the 22nd of July 1209, a force of about 30,000 Crusaders arrived at the walls of Beziers bearing the cross pattee to mislead and create ease among the Cathars, thinking they were friend, not foe, and demanded that about 200 Cathars be surrendered. The people of the town who were mostly Catholic, said that rather than turn over their friends and family, "we would rather be flayed alive."

A mistake by the defenders of Beziers let thousands of attackers in. Arnauld Amaury made the famous quote "Kill them all, God knows his own" on being asked how to tell who were Cathars during the assault. Everyone in the town was killed, some while taking refuge in the church. It is guessed that 20,000 were killed, many of whom were Catholics and not Cathars at all. The crusade became known as the Albigensian crusade after the town of Albi. It was to wipe out the Cathars almost entirely over forty or so years. The Crusaders wanted to go home, but were ordered by the Pope to continue until the whole South of France was controlled and all Cathars were dead. In 1210, they attacked the fortress at Minerv and built "the first great bonfire of heretics" - beginning the practice of burning at the stake that would continue in the Inquisition of the Counter-Reformation

. It is interesting to note that at the siege of Montsegur when the fires were lit the Cathars ran down the hill and threw themselves on, as their beliefs were very strong.

Result Catharism disappeared from the northern Italian cities after the 1260s, pressured by the Inquisition. The last known Cathar perfectus in the Languedoc, Guillaume Bélibaste, was killed in 1321. Other websites http://dannyreviews.com/h/Cathars.html http://gnosistraditions.faithweb.com/mont.html http://www.fordham.edu/halsall/source/gui-cathars.html http://philtar.ucsm.ac.uk/encyclopedia/christ/west/cathar.html http://pages.britishlibrary.net/forrester-roberts/cathars.html Cathar Center in Barcelona: Books, spirituality, exhibition Gnosticism Nontrinitarianism Christianity of the Middle Ages

Cosmology is the branch of astronomy that deals with the origin, structure, evolution and space-time relationships of the universe. NASA defines cosmology as "The study of the structure and changes in the present universe". Another definition of cosmology is "the study of the universe, and humanity's place in it". Modern cosmology is dominated by the Big Bang theory, which brings together observational astronomy and particle physics. Though the word cosmology is recent (first used in 1730 in Christian Wolff's Cosmologia Generalis), the study of the universe has a long history. History Until the Renaissance people thought the universe was only the planets up to Saturn, and stars. With the invention of the telescope, we could see more of the universe. Early in the 20th century, astronomers thought the Milky Way was the entire universe. Later, with astrophotography and spectroscopy, astronomers (for example Edwin Hubble) showed that the Milky Way was only one of many galaxies.

Modern cosmology is considered to have started in 1917 with the final paper of Albert Einstein's theory of general relativity. This made physicists realize that the universe changed. When a scientific discipline begins to change an idea that is believed by many people, it is known as a paradigm shift. During this paradigm shift, the Great Debate took place. Many scientists debated if there were other galaxies. The debate ended when Edwin Hubble found Cepheid Variables in the Andromeda Galaxy in 1926. The Big Bang model was then proposed by Belgian priest, Georges Lemaître in 1927. This was supported by Edwin Hubble's discovery of the redshift in 1929. Later the discovery of cosmic microwave background radiation was made. This was found by Arno Penzias and Robert Woodrow Wilson in 1964.

All of these discoveries have been further supported throughout the 21st century. Some more observations of the cosmic microwave background radiation were found by the COBE, WMAP, and Planck satellites. Some more observations of the redshift were found by the 2dfGRS and SDSS. These are known as redshift surveys. Survey is this context refers to an astronomical survey. An astronomical survey looks at a place in space. A redshift survey is a survey that looks for redshifts. On 1 December 2014, at the Planck 2014 meeting in Ferrara, Italy, astronomers reported that the universe is 13.8 billion years old and is composed of 4.9% regular matter, 26.6% dark matter and 68.5% dark energy. Key terms Mass Gravity Electromagnetic radiation Dark matter Dark energy Speed of light Age of the Universe Related pages String theory Earth science Inflation References Astrophysics

A church is a building that was constructed to allow people to meet to worship together. These people are usually Christians, or influenced by Christianity. Some other non-Christian religious groups also call their religious buildings churches, most notably Scientology. The following description is about Roman Catholic churches, although some parts are the same in Episcopalian and Lutheran churches. Depending on the number of people that are in a community, the churches come in different sizes. Small churches are called chapels. The churches in a particular geographical area form a group called the diocese. Each diocese has a cathedral. In most cases, the cathedral is a very big church. Cathedrals are the seat of bishops. History of church buildings

In the early days of Christianity people met in private buildings. Church buildings are mentioned for the first time around the year 260 A.D. when the Emperor Galienus ordered an end of a persecution and to return the places of worship. In the third century we hear of large church buildings. We do not know, how these early buildings looked. Only in Dura-Europos (Syria) a building was discovered, which had been a private house modified for Christian services. After the death of the Roman emperor Constantine in 337 A.D. Christians were allowed to have buildings to worship in. These first churches were built on a similar plan to Roman basilicas. This plan was later used for the fine Gothic cathedrals and churches that were built at the end of the Middle Ages. The parts of a church There are several parts in the architecture of a church. Not all churches will have all these parts:

The nave is the main part of the church where the congregation (the people who come to worship) sit. The aisles are the sides of the church which may run along the side of the nave. The transept, if there is one, is an area which crosses the nave near the top of the church. This makes the church shaped like a cross, which is a symbol of Jesus's death on a cross. The chancel leads up to the altar at the top of the church. The altar is in the sanctuary. The word “sanctuary” means “sacred place”. People were not allowed to be arrested in the sanctuary, so they were safe. The altar is usually at the east end of the church. People in the church sit facing the altar. We say that the church “faces east”. Churches will also have a tower or steeple, usually at the west end. If the church has a transept the tower may be above the centre of the transept.

In Roman Catholic churches there is always a stoup (bowl) of holy water near the entrance of the church. This tradition comes from the fact that Roman basilicas had a fountain for washing in front of the entrance. The font is a bowl where people (often babies) are baptized. This is also near the entrance of the church. This is a symbol of the fact that it is welcoming the people into the Christian church. Traditionally the nave has long benches for the congregation to sit on. These are called pews. Some churches may now have replaced their pews with chairs so that they can be moved about for different occasions. At the front of the nave is the pulpit where the priest preaches (these talks are called “sermons”). There is also a lectern (like a large music stand) from where the lessons (the Bible readings) are read.

If there are aisles along the side of the nave there will be pillars which hold up the roof. In large churches or cathedrals there may be a row of little arches along the top of these pillars. This is called the triforium. Over the triforium is the clerestory which is a row of windows high up in the church wall. The chancel is the most holy part of the church, and this is why it is often separated from the nave by a screen which can be made of wood or stone, or occasionally iron. The congregation can see through the screen. On the top of the screen there may be a cross. This is called a rood (pronounce like “rude”) screen. Priests used to climb up a staircase to the top of the rood screen to read the epistle and the gospel. Sometimes people sang from there.

Inside the chancel are the benches where the choir sit. These are called choir stalls. They are on both sides. The two sides of the choir sit facing one another. The choir members who sit on the left (north side) are called “cantoris” (the side where the “cantor” sits) and those on the right (south side) are called “decani” (the side where the deacon sits). In some large churches or cathedrals the seats for the priests tip up. The top of these seats, when they are tipped up, are called misericords (from the Latin word for “mercy”). This is because the priests or monks were able to lean against them when they got tired if they had to stand up for a long time. Sometimes there are holes in the walls of the screen so that the congregation can see through. These are called squints. If there is a recess in the wall it is called an aumbry. It is a cupboard for communion wine and bread that have been consecrated by a priest.

The altar may be right at the east end of the church, but in larger churches or cathedrals it is often much farther forward. In that case the very east end is called an apse. Sometimes it is a separate chapel called the “Lady Chapel”. Churches through the ages The design of churches changed a lot during the course of history. Often churches were made bigger. When this happened there may be a mixture of architectural styles. These styles vary a lot in different countries. English churches In English churches there were several different periods of architecture:

The Saxon period (700–1050) was a time when churches were very simple. The end of the church (end of the sanctuary) was often rounded. Hardly any are left now because they were mostly made of wood. The Norman period (1050–1190) came from the style called Romanesque which was popular in Europe. The arches had ornaments which were called “mouldings”. The tops of the pillars looked like cushions, so they were called “cushion capitals”. The windows were narrow and rounded at the top. Early English or Gothic architecture (1190–1280) was not as solid and heavy as Norman architecture. Towers were elegant and tall, like the tower of Salisbury Cathedral. The Decorated style of architecture (1280–1360)was popular at a time when the plague (Black Death) was raging and a third of the people in England died. For that reason, not so much building was done then. There were lots of stone carvings were made in churches at that time.

The Perpendicular style (1360–1540) was very grand. It had lots of straight upward lines and fan vaulting. This can be seen in Westminster Abbey and King's College Chapel, Cambridge. Many churches that can be seen in England were built in this period.

In the 1600s, churches were built in a variety of styles. Often they copied some of the older styles. After the Great Fire of London many new churches were built by the architect Sir Christopher Wren. They were built in the classical style. Churches continued to be built in later centuries like this, but also the Gothic style continued to be used. Modern churches often do not have the traditional cross-shape. It is difficult for the congregation to see and hear what is happening in the chancel. Modern churches bring the congregation, choir and priests in closer touch. An example is the round design for the Church of Christ the Cornerstone in Milton Keynes. Modern churches are often simpler but with a warmer character than the Gothic churches. Many have beautiful mosaic glass windows. Coventry Cathedral is a famous example of a modern church building. Related pages Cathedral Chapel Choir (music) References Encyclopædia Britannica, 1973 Other websites Virtual Church

A city is a place where many people live close together. A city has many buildings and streets. It has houses, hotels, condominiums, and apartments for many people to live in, shops where they may buy things, places for people to work, and a government to run the city and keep law and order in the city. People live in cities because it is easy for them to find and do everything they want there. A city usually has a "city center" where government and business occur and suburbs where people live outside the center. Definition No rule is used worldwide to decide why some places are called "city," and other places are called "town."

Some things that make a city are : A long history. Although many cities today have only been around for tens or hundreds of years, there are a few which have been so for thousands of years. For example, Athens, Greece was founded in 1000 BC and Rome, Italy has existed since 700 BC. A large population. Cities can have millions of people living in and around them. Among them are Tokyo, Japan, and the Tokyo Metropolis around it, which includes Yokohama and Chiba. In Japan, the population of a city ( 市 ) is at least over 50,000 people. and among cities, there are various grades according to laws, which the central government of Japan governs.

A center where business and government takes place. The first case is often described as the financial capital, such as Frankfurt in Germany. The second case is true for different levels of government, whether they are local or part of a larger region (for example, Atlanta, Georgia, or the capital of the United States Washington, D.C.) Cities that contain the government of the region it is in are called capitals. Almost every country has its own capital. Special powers called town privileges which have been given by the government of the country or its ruler. Europe during the Middle Ages was a great example of having town privileges. Having a cathedral or a university. This rule is found in the United Kingdom. The smallest "cathedral cities" are St. David's and St. Asaph's which are both in Wales, Ripon and Wells which are in England.

In American English, people often call all places where many people live cities. (See below: Size of cities ) Size of cities The sizes of cities can be very different. This depends on the type of city. Cities built hundreds of years ago and which have not changed much are much smaller than modern cities. There are two main reasons. One reason is that old cities often have a city wall, and most of the city is inside it. Another important reason is that the streets in old cities are often narrow. If the city got too big, it was hard for a cart carrying food to get to the marketplace. People in cities need food, and the food always has to come from outside the city.

Cities that were on a river like London could grow much bigger than cities that were on a mountain like Sienna in Italy, because the river made a transport route for carrying food and other goods, as well as for transporting people. London has been changing continually for hundreds of years, while Sienna, a significant city in the 1300s, has changed very little in 700 years. Modern cities with modern transport systems can grow very large, because the streets are wide enough for cars, buses, and trucks, and there are often railway lines. In the US, the word city is often used for towns that are not very big. When the first European people went to America, they named " city " to new places. They hoped the places would be great cities in the future. For example, Salt Lake City was the name given to a village of 148 people. When they started building the town, they made street plans and called it Great Salt Lake City (for the nearby Great Salt Lake). Now, 150 years later, it really is a big city.

In modern times many cities have grown bigger and bigger. The whole area is often called a "metropolis" and can sometimes include several small ancient towns and villages. The metropolis of London includes London, Westminster, and many old villages such as Notting Hill, Southwark, Richmond, Greenwich, etc. The part that is officially known as the " City of London " only takes up one square mile. The rest is known as "Greater London. " Many other cities have grown in the same way. These giant cities can be exciting places to live, and many people can find good jobs there, but modern cities also have many problems. Many people cannot find jobs in the cities and have to get money by begging or by crime. Automobiles, factories, and waste create a lot of pollution that makes people sick. Urban history

Urban history Urban history is history of civilization. The first cities were made in ancient times, as soon as people began to create civilization . The oldest city on Earth is probably Catal Huyuk, which existed from 7500BCE to 6500bce, although mainstream historians consider Catal Huyuk to be a proto-city.Famous ancient cities which fell to ruins included Babylon, Troy, Mycenae and Mohenjo-daro. Benares in northern India is one among the ancient cities which has a history of more than 3000 years. Other cities that have existed since ancient times are Athens in Greece, Rome and Volterra in Italy, Alexandria in Egypt and York in England. In Europe, in the Middle Ages, being a city was a special privilege, granted by nobility. Cities that fall into this category, usually had (or still have) city walls. The people who lived in the city were privileged over those who did not. Medieval cities that still have walls include Carcassonne in France, Tehran in Iran, Toledo in Spain and Canterbury in England.

Features Infrastructure People in a city live close together, so they cannot grow all their own food or gather their own water or energy. People also create waste and need a place to put it. Modern cities have infrastructure to solve these problems. Pipes carry running water, and power lines carry electricity. Sewers take away the dirty water and human waste. Most cities collect garbage to take it to a landfill, burn it, or recycle it. Transport is any way of getting from one place to another. Cities have roads which are used by automobiles (including trucks), buses, motorcycles, bicycles, and pedestrians (people walking). Some cities have trains and larger cities have airports. Many people in cities travel to work each day, which is called commuting.

Buildings and design Houses and apartments are common places to live in cities. Great numbers of people in developing countries (and developed countries, in the past) live in slums. A slum is poorly built housing, without clean water, where people live very close together. Buildings are usually taller in the city center, and some cities have skyscrapers. City streets can be shaped like a grid, or as a "wheel and spokes": a set of rings and lines coming out from the center. Streets in some older cities like London are arranged at random, without a pattern. The design of cities is a subject called urban planning. One area of the city might have only shops, and another area might have only factories. Cities have parks, and other public areas like city squares. United States politics