What Is The Internet?
Ted Stevens, former U.S. Senator from Alaska, used to be the head of a committee that regulates the Internet in the United States. He became famous for many things, but one of them was when he tried to describe the Internet. He tries to use a metaphor (tubes) to explain bandwidth issues, but he ends up sounding like a crazy man.
The Internet is, simply put, billions of computers worldwide connected together under the TCP/IP protocol. If your computer is connected to the Internet, that means that it is now a part of that network.
Now, how does that work? What does that look like?
Take the computers in the lab you are working in. Our lab has 24 computers (including my laptop), plus two printers connected to the network. All the devices are connected by hubs, and all are connected to the network server (which also acts as a file server). The network server, in turn, is connected to the Internet. See the map below, where red squares are computers, green triangles are printers, yellow circles are hubs, the purple lines are LAN cables, and the blue pentagon is our server. The light blue avenue is a fiber-optic connection to the Internet:
Our server, the blue pentagon above, is in turn connected to other servers at our ISP, which is connected to more servers across the country. There is a large web of connections between computers and servers all across the world, which makes it possible for your computer to contact almost any other computer in the world. This is the Internet.
There are many ways you could map the Internet; one way of doing it, representing many (but not even close to all) of the web servers on the main transmission lines of the Internet, is shown below. Now, keep in mind that our little lab here is not even on this map—it's too small. No, our server is one of many servers connected to a larger server which is at the very end of just one of the tiny lines somewhere on this map:
In this map, the end of every small thread is a server, which can host up to 256 other servers; each server can host hundreds more computers each. Each junction of lines is also a server. You get the idea of how big things are: there are a lot of computers linked together.
This is not a perfect representation, but it perhaps begins to give you an idea of what the mass of connections looks like. The important thing to remember, however, is that it is just a network—it is a lot of computers connected together. It may be impressive because of its size, but what makes the Internet work is protocols.
A Brief History of the Internet
The concept of the Internet had been around since 1960, when J. C. R. Licklider proposed an idea to network computers so that libraries could share computer data. Licklider was hired by the Advanced Research Projects Agency (ARPA), a research unit for the United States military. His idea was later developed into a network called ARPANET. On October 29, 1969, the first connection between two computers on this network was tested. It crashed after just 3 letters were typed, but it was the beginning of what we now call the Internet.
One thing was missing, however: a way for different computers, with different systems, to communicate reliably with each other. Robert E. Kahn and Vinton Cerf solved this problem by creating a set of protocols in 1974 which later became known as "TCP/IP." The 1974 proposal was the first time anyone had used the word "Internet," which was short for "internetworking." The TCP/IP protocol set was mostly completed by 1978.
In 1983, the military created its own network named "MilNet," and left the ARPANET to US government organizations like NASA, the Department of Energy, and the NSF, or the National Science Foundation. The NSF started a network called "NSFNET," which grew and was expanded, and was eventually transformed in 1995 into the "Internet" that we know today.
Over this time, many people had gotten experience using the network. I remember as a teenager visiting my sister's part-time work at Stanford University. In her office they were using computers to connect to networks, most likely ARPANET. By the 1980's, many people in business and education started using the Internet. Around 1980, discussion groups (Usenet) came into use (I remember using them; they always reminded users that the system required a great deal of money, and warned people not to use them unnecessarily). The same system also helped introduce e-mail, a technology that had been used for almost 10 years on ARPANET before that time.
Soon, more and more people had used or heard about these computer networks. E-mail was appreciated as a wonderful convience, and many wanted the ability to access information electronically. However, public networks like NSFNET could not be used commercially. As a result, many private companies began their own "private Internets," called online services. Some names you have perhaps never heard of, like GEnie and Prodigy; you might have heard of CompuServe, and you almost certainly have heard of AOL (America On Line).
These private online services began to gain popularity in the early 1990's. Most were text-based, and all were private—they did not link to each other, and did not allow access to the Internet. All of them were content providers, meaning that they offered valued information, such as stock prices, weather, news, sports news, and entertainment information. They also provided discussion areas, and allowed users to send email to each other (although again, not to users of competing networks). At that time, I used a service called GEnie, provided by General Electric Corporation. I recall that there was a TV show being developed called Babylon 5; the shows writer and producer, J. Michael Straczynski, made a kind of home base on GEnie and talked directly to fans about production of the TV show.
These services were not so easy to use, however. There were no "Internet connections" or ISPs at the time. To connect to the Internet, a user had to buy a machine called a "modem." This machine used a standard telephone connection. The computer would dial up a local telephone number, and use audio signals to transmit data. My own fisrt modem ran at the speed of 300 baud, or 300 bits per second. Today, a home connection in Tokyo may be 1 Gigabit per second, or 1,000,000,000 baud! The data transfer was so slow that most interfaces had to use text only, or else low-quality graphics. I remember seeing photos downloaded; you would wait several minutes while the image appeared, line by line. In additon to being slow, the connection used the telephone line. If someone picked up a telephone and tried to use it, or if a call came, you would lose your connection.
All of this changed in the mid 1990's with advent of the World Wide Web, browsers, and Internet Service Providers.