The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve several billion 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 an extensive range of information resources and services, such as the inter-linked hypertext documents of the World Wide Web, the infrastructure to support email, and peer-to-peer networks.
Internet has enabled and accelerated new forms of human interactions through instant messaging, Internet forums, and social networking. Business-to-business and financial services on the Internet affect supply chains across entire industries. The origins of the Internet reach back to research commissioned by the United States government in the 1960s to build robust, fault-tolerant communication via computer networks. While this work together with work in the United Kingdom and France lead to important precursor networks, they were not the Internet. The funding of a new U.S. backbone by the National Science Foundation in the 1980s, as well as private funding for other commercial backbones, led to worldwide participation in the development of new networking technologies, and the merger of many networks.
Research into packet switching started in the early 1960s and packet switched networks such as Mark I at NPL in the UK, ARPANET, CYCLADES, Merit Network, Tymnet, and Telenet, were developed in the late 1960s and early 1970s using a variety of protocols. The ARPANET in particular led to the development of protocols for internetworking, where multiple separate networks could be joined together into a network of networks.
Early international collaborations on ARPANET were sparse. For various political reasons, European developers were.