Internet and the World Wide Web
The Internet did have a parent in a program called ARPANET, the Advanced Research Projects Agency Network. The United States Department of Defense developed ARPANET in 1969 as a network for organizations involved in defense research and as a secure communications system that would also survive attack. One of the characteristics of ARPANET was that its data were transmitted in so-called packets that were small parts of the longer messages the computers were exchanging. By segmenting the data and sending it by packet-switching, fewer problems in data transfer occurred. The system also had fault tolerance, which meant that communication errors could happen without shutting down the whole system.
When researchers began extending ARPANET into other applications, the National Science Foundation (NSF) adapted ARPANET's TCP/IP protocols to its own NSFNET network with many potential layers and the ability to carry far more communications. In fact, many other education and research organizations formed other networks in the 1980s; the Computer + Science Network (CSNET), the National Aeronautics and Space Administration (NASA), and the Department of Education (DOE) were among these. The need to make these networks a seamless operation was addressed when the National Research and Education Network (NREN) was formed, and it smoothed operations to make the Internet the network of all networks. By 1990, ARPANET ceased to exist because it had been fully replaced by the Internet.
While government and academic entities were developing networks that eventually combined under the infrastructure of the Internet, some businesses created successful networks of their own. Perhaps the most famous of these was Ethernet, a creation of Xerox Corporation that, in 1974, enabled all the machines in a single location to communicate with each other. In 1991, the Commercial Internet Exchange or CIX was formed by businesses with their own large networks. CIX is a high-speed interconnection point that allowed the member networks to exchange information for commercial purposes. CIX was largely independent of the NSFNET. Today, the Internet seems like one massive entity, and these separate networks are not easily distinguished in the global workings of the Internet.
The NSF remains actively involved in the operations and future of the Internet as one of several organizations that administers the Internet. The Internet Network Information Center (InterNIC) and the Internet Architecture Board (IAB) name networks and computers and resolve conflicts. Other organizations develop and administer protocols and engineer the complex interrelationships of networks.
While the Internet was evolving, need arose for methods for independent computer users to access the Internet. Within businesses, educational institutions, and government organizations, the Internet is accessed through a LAN or Local Area Network that provides service to all the employees of a company, for example, and is also a stepping-off point for Internet access. Independent users contract with commercial access providers to obtain Internet access. The commercial access providers are hosts to the Internet. They include America Online, Compuserve, Netcom, AT&T, and many other nationwide and local providers.
Internet communications use a number of other technologies. Services are transmitted by television cables, satellites, fiber optics, and radio. Cable television wires are steadily becoming more popular especially among users who want high-speed Internet services termed "broadband" services. Most consumers use modems (devices that translate electrical signals to sound signals and back) as the means of accessing the Internet through telephone lines. Special cable modems have speeds of 1.5 million bits (units of computer information) per second compared to the 56,000 (56k) bits per second (bps) of standard modems. Telephone companies also provide Digital Subscriber Line services that use a wider range of frequencies over regular telephone lines and can transmit data at 7 million bps (Mbps). Interest in cable net connections is outpacing the introduction of technologies like color television or cellular phones.
- Internet and the World Wide Web - Evolution Of The World Wide Web
- Internet and the World Wide Web - Overview Of The Internet
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