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Chapter 49. Internet Basics > What Is Bandwidth? - Pg. 216

Internet Basics 216 What Is the Internet? The Internet is a global network of computers. Any computer connected to the Internet can com- municate with any other computer connected to the Internet. Think of it like a worldwide highway system. You can get from any highway to any other highway, though not necessarily via a direct route. The Internet even has rules of the road, called protocols, that determine how data gets from one connected computer to another. How Did the Internet Get Started? The Internet began life in 1969 as the Arpanet, a network designed to let government researchers across the country share computer resources. More and more universities and government agen- cies were added to the network over the '70s, and in the late '80s it was opened to commercial traffic. No one owns or even governs the Internet now. It's a decentralized network that is supported by the companies and institutions that access it. Network administration (such as deciding on new types of domains) is overseen by a committee called ICANN (www.icann.org). How Does Information Travel on the Internet? Information sent over the Internet can travel directly from your ISP to that of the person you're communicating with, but often it travels an indirect route. In fact, messages are sometimes broken apart into smaller pieces or packets. Each packet may travel a different route to its destination. Then all the packets are reassembled into the single message. This is called packet switching, and you'll sometimes hear real geeks refer to the Internet as a "packet-switched network." The Internet can handle all types of digital data including text, numbers, programs, illustrations, photographs, audio, animation, and video. Anything you can view on a computer screen or hear through computer speakers can be transmitted over the Internet. But it's not (yet!) possible to trans- port objects or people. What Is Bandwidth? Think of the Internet as a system of pipes that carry data. Little pipes can carry only a small amount of data, but larger pipes can carry more data. Bandwidth refers to the size of the metaphorical pipe, or the amount of data that can be handled at any one time. So more bandwidth not only means that more people can use the Internet at the same time, it also means that people can work with larger files. Text and numbers take up relatively little bandwidth but audio takes up more and video a great deal more. A single photograph can take up as much bandwidth as thousands of words, making the old adage, "a picture's worth a thousand words," a bit of an understatement. What Is the World Wide Web? The World Wide Web has become extremely popular because it is easy to use and provides many different types of information. The key to the Web is hypertext, which was developed in 1989 by Tim Berners-Lee at CERN, the European Laboratory for Particle Physics in Geneva, as a way to coor- dinate information around the world. It's a system that uses what we now call hyperlinks or just plain links, which transfer users from one Web page to another with the click of a mouse.