Internet

The Internet is a global system of interconnected computer networks that use the standard Internet Protocol Suite (TCP/IP) to serve billions of users worldwide. It is a network of networks that consists of millions of private, public, academic, business, and government networks, of local to global scope, that are linked by a broad array of electronic, wireless and optical networking technologies.The Internet carries a vast range of information resources and services, such as the inter-linked hypertext documents of the World Wide Web (WWW) and the infrastructure to support electronic mail.

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Terminology
Internet is a short form of the technical term internetwork,[1] the result of interconnecting computer networks with special gateways or routers. The Internet is also oftenreferred to as the Net.

Professor Leonard Kleinrock with the first ARPANET Interface Message Processors at UCLA
The first two nodes of what would become the ARPANET were interconnected between Leonard Kleinrock's Network Measurement Center at the UCLA's School of Engineering and Applied Science and Douglas Engelbart's NLS system at SRI International (SRI) in Menlo Park, California, on 29 October1969.[9]

T3 NSFNET Backbone, c. 1992
In 1982 the Internet Protocol Suite (TCP/IP) was standardized and the concept of a world-wide network of fully interconnected TCP/IP networks called the Internet was introduced. Access to the ARPANET was expanded in 1981 when the National Science Foundation (NSF) developed the Computer Science Network (CSNET). In December 1974, RFC 675 – Specification ofInternet Transmission Control Program, by Vinton Cerf, Yogen Dalal, and Carl Sunshine, used the term internet, as a shorthand for internetworking; later RFCs repeat this use, so the word started out as an adjective rather than the noun it is today.[14]

This NeXT Computer was used by Sir Tim Berners-Lee at CERN and became the world's first Web server.
Since the mid-1990s the Internet has had atremendous impact on culture and commerce, including the rise of near instant communication by electronic mail, instant messaging, Voice over Internet Protocol (VoIP) "phone calls", two-way interactive video calls, and the World Wide Web[20] with its discussion forums, blogs, social networking, and online shopping sites. Increasing amounts of data are transmitted at higher and higher speeds over fiberoptic networks. The Internet continues to grow, driven by ever greater amounts of online information and knowledge, commerce, entertainment and social networking.[21]
Structure
The Internet structure and its usage characteristics have been studied extensively. It has been determined that both the Internet IP routing structure and hypertext links of the World Wide Web are examples of scale-freenetworks.[29] 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, Internet2, and the UK's national research and education network JANET. These in turn are built around smaller networks (see also the list of academic computer network organizations).
Governance
The Internetis a globally distributed network comprising many voluntarily interconnected autonomous networks. It operates without a central governing body. However, to maintain interoperability, all technical and policy aspects of the underlying core infrastructure and the principal name spaces are administered by the Internet Corporation for Assigned Names and Numbers (ICANN), headquartered in Marina del Rey,California. ICANN is the authority that coordinates the assignment of unique identifiers for use on the Internet.
Modern uses
The Internet allows greater flexibility in working hours and location, especially with the spread of unmetered high-speed connections. The Internet can be accessed almost anywhere by numerous means, including through mobile Internet devices. Mobile phones, datacards,...