The Internet is the global system of interconnected mainframe, personal, and wireless computer networks that use the Internet protocol suite (TCP/IP) to link billions of devices worldwide. It is a network of networks that consists of millions of private, public, academic, business, and government networks of local to global scope, 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-linkedhypertext documents and applications of the World Wide Web (WWW), electronic mail, Usenet newsgroups, telephony, and peer-to-peer networks for file sharing.
Although the Internet protocol suite has been used by academia and the military industrial complex since the early 1980s, rapid adoption of its use was driven by events of the late 1980s and 1990s such as more powerful and affordable computers, the advent offiber optics, the popularization of HTTP and the Web browser, and a push towards opening the technology to commerce. Internet use grew rapidly in the West from the mid-1990s and from the late 1990s in the developing world. In the 21 years since 1995, Internet use has grown 100-times to reach over one third of the world population,leading to its services and technologies being incorporated into virtually every aspect of contemporary life. The impact of the Internet has been so immense that it has been referred to as the "8th continent".
The origins of the Internet date back to research and development commissioned by the United States government, the United Kingdom government and the government of France in the 1960s to build robust, fault-tolerant communication via computer networks. This work led to the primary precursor networks: the ARPANET, in the United States, the Mark 1 NPL network in the United Kingdom and CYCLADES in France.The interconnection of regional academic networks in the 1980s marks the beginning of the transition to the modern Internet From the late 1980s onward, the network experienced sustained exponential growth as generations of institutional, personal, and mobile computers were connected to it.
Most traditional communications media, including telephony and television, are being reshaped or redefined by the Internet, giving birth to new services such as Internet telephony and Internet television. Newspaper, book, and other print publishing are adapting to website technology, or are reshaped into blogging and web feeds. The entertainment industry was initially the fastest growing segment on the Internet. The Internet has enabled and accelerated new forms of personal interactions through instant messaging, Internet forums, and social networking. Online shopping has grown exponentially both for major retailers and small artisans and traders. Business-to-business and financial services on the Internet affect supply chains across entire industries.
The Internet has no centralized governance in either technological implementation or policies for access and usage; each constituent network sets its own policies.Only the overreaching definitions of the two principal name spaces in the Internet, the Internet Protocol address space and the Domain Name System (DNS), are directed by a maintainer organization, the Internet Corporation for Assigned Names and Numbers (ICANN). The technical underpinning and standardization of the core protocols are an activity of theInternet Engineering Task Force (IETF), a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise.