(1) (Lower case "i" internet) A large network made up of a number of smaller networks.|
(2) (Upper case "I" Internet) The global network of networks composed of nearly a billion computers in more than 100 countries. Originally developed for the U.S. military, it became widely used for academic and commercial research, with access to unpublished data and journals on many subjects. Today, the "Net" is the world's largest source of information on every subject known to humankind and the world's largest mail-order catalog. By 2005, more than one billion people were using the Internet.
E-Mail Lit the Fuse
In the mid-1990s, the Internet surged in growth, increasing a hundredfold in 1995 and 1996 alone. The first reason was that up to that point, the major online services, such as AOL and CompuServe, provided e-mail only to their own customers. As they began to reach out to Internet users by interfacing with the Internet's mail system, the Internet automatically took on the role of global switching center. An AOL member could, for the first time, send an e-mail message to a CompuServe member, and vice versa. The Internet's mail protocol glued the world together for messaging, and eventually every service adopted it as the standard (see SMTP).
The Bomb Exploded with the Web
Secondly, with the advent of graphics-based Web browsers such as Mosaic and Netscape Navigator, and soon after, Microsoft's Internet Explorer, the World Wide Web took off. The Web became available to users with PCs and Macs rather than only scientists and programmers at Unix workstations. Delphi was the first proprietary online service to offer Web access, and the others followed. Rising out of the woodwork, Internet service providers (ISPs) offered access to everyone, and the Web grew exponentially. Web pages became the majority of Internet traffic (see HTTP and HTML).
Although daily news and information is available on countless Web sites, long before the Web, information on myriad subjects was exchanged via Usenet (User Network) newsgroups. Still thriving, newsgroup articles can be selected and read directly from a Web browser. See Usenet.
Chat rooms provide another popular Internet service. Internet Relay Chat (IRC) offers multiuser text conferencing on diverse topics. Dozens of IRC servers provide hundreds of channels that anyone can log in to and participate via the keyboard. See IRC.
The Original Internet
The Internet started in 1969 as the ARPAnet. Funded by the U.S. government, ARPAnet became a series of high-speed links between major supercomputer sites and educational and research institutions worldwide, although mostly in the U.S. A major part of its backbone was the National Science Foundation's NSFNet. Along the way, it became known as the "Internet" or simply "the Net." By the 1990s, so many networks had become part of it and so much traffic was not educational or pure research in nature that it became obvious that the Internet was on its way to becoming a commercial venture.
It Went Commercial in 1995
In 1995, the Internet was turned over to large commercial Internet providers (ISPs), such as MCI, Sprint and UUNET, which took responsibility for the backbones and have increasingly enhanced their capacities ever since. Regional ISPs link into these backbones to provide lines for their subscribers, and smaller ISPs hook either directly into the national backbones or into the regional ISPs.
The TCP/IP Protocol
Internet computers use the TCP/IP communications protocol. There are hundreds of millions of hosts on the Internet, a host being a server of any size that is always online via TCP/IP and providing e-mail or Web or some Internet-based service. The Internet is also connected to non-TCP/IP networks worldwide through gateways that convert TCP/IP into other protocols. See TCP/IP.
Internet Life Before the Web
Before the Web and graphics-based Web browsers, academicians and scientists accessed the Internet using command-driven Unix utilities. Some of these utilities are still widely used and are available for all platforms. For example, FTP (file transfer program) is used to upload and download files, and Telnet lets a user log in to an Internet host and run a program. See FTP, Telnet, Archie, Gopher and Veronica.
The Next Internet
Ironically, some of the original academic and scientific users of the Internet have developed their own Internet once again. Internet2 is a high-speed academic research network that was started in much the same fashion as the original Internet (see Internet2). See Web vs. Internet, World Wide Web, how to search the Web, intranet, NAP, hot topics and trends, IAB, information superhighway and online service.
These four nodes were drawn in 1969 showing the University of California at Berkeley and Los Angeles, SRI International and the University of Utah. This modest network diagram was the beginning of the ARPAnet and eventually the Internet. (Image courtesy of The Computer History Museum, www.computerhistory.org)
Small Internet service providers (ISPs) hook into regional ISPs, which link into major backbones that traverse the U.S. This diagram is conceptual because ISPs often span county and state lines.