internet

HOW INTERNET STARTED IT IS QUITE INTERSTING STROREY. Terminology: Internet vs. Web The Internet and the World Wide Web are not synonymous: the Internet is a collection of interconnected computer networks, linked by copper wires, fiber-optic cables, wireless connections, etc.; the Web is a collection of interconnected documents and other resources, linked by hyperlinks and URLs. The World Wide Web is accessible via the Internet, as are many other services including e-mail, file sharing, and others described below. The best way to define and distinguish between these terms is with reference to the Internet protocol suite. This collection of standards and protocols is organized into layers such that each layer provides the foundation and the services required by the layer above. In this conception, the term Internet refers to computers and networks that communicate using IP (Internet protocol) and TCP (transfer control protocol). Once this networking structure is established, then other protocols can run “on top.” These other protocols are sometimes called services or applications. Hypertext transfer protocol, or HTTP, is the application layer protocol that links and provides access to the files, documents and other resources of the World Wide Web. Creation of the Internet For more details on this topic, see History of the Internet. The neutrality or factuality of this article or section may be compromised by weasel words. You can help Wikipedia by improving weasel-worded statements. The USSR's launch of Sputnik spurred the United States to create the Advanced Research Projects Agency (ARPA, later known as the Defense Advanced Research Projects Agency, or DARPA) in February 1958 to regain a technological lead. ARPA created the Information Processing Technology Office (IPTO) to further the research of the Semi Automatic Ground Environment (SAGE) program, which had networked country-wide radar systems together for the first time. J. C. R. Licklider was selected to head the IPTO, and saw universal networking as a potential unifying human revolution. In 1950, Licklider moved from the Psycho-Acoustic Laboratory at Harvard University to MIT where he served on a committee that established MIT Lincoln Laboratory. He worked on the SAGE project. In 1957 he became a Vice President at BBN, where he bought the first production PDP-1 computer and conducted the first public demonstration of time-sharing. Licklider recruited Lawrence Roberts to head a project to implement a network, and Roberts based the technology on the work of Paul Baran who had written an exhaustive study for the U.S. Air Force that recommended packet switching (as opposed to Circuit switching) to make a network highly robust and survivable. After much work, the first node went live at UCLA on October 29, 1969 on what would be called the ARPANET, one of the "eve" networks of today's Internet. Following on from this, the British Post Office, Western Union International and Tymnet collaborated to create the first international packet switched network, referred to as the International Packet Switched Service (IPSS), in 1978. This network grew from Europe and the US to cover Canada, Hong Kong and Australia by 1981. The first TCP/IP wide area network was operational by 1 January 1983, when the United States' National Science Foundation (NSF) constructed a university network backbone that would later become the NSFNet. (This date is held by some to be technically that of the birth of the Internet.) It was then followed by the opening of the network to commercial interests in 1985. Important, separate networks that offered gateways into, then later merged with, the NSFNet include Usenet, BITNET and the various commercial and educational X.25 Compuserve and JANET. Telenet (later called Sprintnet), was a large privately-funded national computer network with free dialup access in cities throughout the U.S. that had been in operation since the 1970s. This network eventually merged with the others in the 1990s as the TCP/IP protocol became increasingly popular. The ability of TCP/IP to work over these pre-existing communication networks, especially the international X.25 IPSS network, allowed for a great ease of growth. Use of the term "Internet" to describe a single global TCP/IP network originated around this time. The network gained a public face in the 1990s. On August 6, 1991 CERN, which straddles the border between France and Switzerland publicized the new World Wide Web project, two years after Tim Berners-Lee had begun creating HTML, HTTP and the first few Web pages at CERN. An early popular Web browser was ViolaWWW based upon HyperCard. It was eventually replaced in popularity by the Mosaic Web Browser. In 1993 the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign released version 1.0 of Mosaic and by late 1994 there was growing public interest in the previously academic/technical Internet. By 1996 the word "Internet" was coming into common daily usage, frequently misused to refer to the World Wide Web. Meanwhile, over the course of the decade, the Internet successfully accommodated the majority of previously existing public computer networks (although some networks such as FidoNet have remained separate). This growth is often attributed to the lack of central administration, which allows organic growth of the network, as well as the non-proprietary open nature of the Internet protocols, which encourages vendor interoperability and prevents any one company from exerting too much control over the network. Today's Internet A rack of servers.Aside from the complex physical connections that make up its infrastructure, the Internet is facilitated by bi- or multi-lateral commercial contracts (e.g., peering agreements), and by technical specifications or protocols that describe how to exchange data over the network. Indeed, the Internet is essentially defined by its interconnections and routing policies. As of January 11, 2007, 1.093 billion people use the Internet according to Internet World Stats. Internet protocols For more details on this topic, see Internet Protocols. In this context, there are three layers of protocols: At the lowest level is IP (Internet Protocol), which defines the datagrams or packets that carry blocks of data from one node to another. The vast majority of today's Internet uses version four of the IP protocol (i.e. IPv4), and although IPv6 is standardized, it exists only as "islands" of connectivity, and there are many ISPs who don't have any IPv6 connectivity at all. [1] Next come TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) - the protocols by which one host sends data to another. The former makes a virtual 'connection', which gives some level of guarantee of reliability. The latter is a best-effort, connectionless transport, in which data packets that are lost in transit will not be re-sent. On top comes the application protocol. This defines the specific messages and data formats sent and understood by the applications running at each end of the communication. Internet structure There have been many analyses of the Internet and its structure. For example, it has been determined that the Internet IP routing structure and hypertext links of the World Wide Web are examples of scale-free networks. Similar to the way the commercial Internet providers connect via Internet exchange points, research networks tend to interconnect into large subnetworks such as: GEANT GLORIAD Abilene Network JANET (the UK's Joint Academic Network aka UKERNA) These in turn are built around relatively smaller networks. See also the list of academic computer network organizations In network schematic diagrams, the Internet is often represented by a cloud symbol, into and out of which network communications can pass. ICANN For more details on this topic, see ICANN. The Internet Corporation for Assigned Names and Numbers (ICANN) is the authority that coordinates the assignment of unique identifiers on the Internet, including domain names, Internet protocol addresses, and protocol port and parameter numbers. A globally unified namespace (i.e., a system of names in which there is one and only one holder of each name) is essential for the Internet to function. ICANN is headquartered in Marina del Rey, California, but is overseen by an international board of directors drawn from across the Internet technical, business, academic, and non-commercial communities. The US government continues to have the primary role in approving changes to the root zone file that lies at the heart of the domain name system. Because the Internet is a distributed network comprising many voluntarily interconnected networks, the Internet, as such, has no governing body. ICANN's role in coordinating the assignment of unique identifiers distinguishes it as perhaps the only central coordinating body on the global Internet, but the scope of its authority extends only to the Internet's systems of domain names, Internet protocol addresses, and protocol port and parameter numbers. On Nov. 16, 2005, the World Summit on the Information Society, held in Tunis, established the Internet Governance Forum (IGF) to discuss Internet-related issues. Language For more details on this topic, see English on the Internet. The prevalent language for communication on the Internet is English. This may be a result of the Internet's origins, as well as English's role as the lingua franca. It may also be related to the poor capability of early computers to handle characters other than those in the basic Latin alphabet. Further information: Unicode After English (30% of Web visitors) the most-requested languages on the World Wide Web are Chinese 14%, Japanese 8%, Spanish 8%, German 5%, and French 5% (from Internet World Stats, updated January 1