The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite (TCP/IP) to link several billion devices worldwide. It is a network of networks[1] 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-linked hypertext documents and applications of the World Wide Web (WWW), the infrastructure to support email, and peer-to-peer networks for file sharing and telephony.

The origins of the Internet date back to research commissioned by the United States government in the 1960s to build robust, fault-tolerant communication via computer networks.[2] This work, combined with efforts in the United Kingdom and France, led to the primary precursor network, the ARPANET, in the United States. The interconnection of regional academic networks in the 1980s marks the beginning of the transition to the modern Internet.[3] From the early 1990s, the network experienced sustained exponential growth as generations of institutional, personal, and mobile computers were connected to it.

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.[4] Though the Internet has been widely used by academia since the 1980s, the commercialization of what was by the 1990s an international network resulted in its popularization and incorporation into virtually every aspect of modern human life. As of December 2014, 37.9 percent of the world's human population has used the services of the Internet within the past year--over 100 times more people than were using it in 1995.[5][6] Internet use grew rapidly in the West from the mid-1990s to early 2000s and from the late 1990s to present in the developing world. In 1994 only 3% of American classrooms had access to the Internet, while by 2002 that figure was 92%.[