Internet

The internet is a global system of interconnected computer networks that use the Internet protocol suite (TCP/IP) to link devices worldwide. It enables a wide range of information resources and services, including the Web, email, and file exchange, and connects billions of endpoints such as computers, smartphones, and sensors.

Its origins lie in late 1960s research networks funded by the U.S. Department of Defense and academic collaborations, notably ARPANET. Protocols for packet switching and TCP/IP were standardized in the 1970s and 1980s, enabling diverse networks to interconnect. The NSFNET backbone in the 1980s, followed by rapid commercialization in the 1990s, expanded public access. The World Wide Web, proposed by Tim Berners-Lee in 1989 and implemented in 1991, popularized the Internet.

The Internet relies on packet switching and routing. Data are broken into packets, transmitted via routers across interconnected networks, and reassembled at the destination. Core components include the IP addressing scheme, the Domain Name System, and backbone networks. Access is provided through various media, including copper, fiber, and wireless links.

Common Internet services include email, file transfer (FTP), the World Wide Web (HTTP/HTTPS), instant messaging, and VoIP. The Web is a vast collection of interlinked documents and resources accessed through web browsers. Protocols such as TCP, UDP, DNS, and HTTP underpin these services.

Standards and coordination are provided by international organizations, led by the Internet Engineering Task Force (IETF) and the Internet Corporation for Assigned Names and Numbers (ICANN). IANA manages global DNS root zone and allocation of IP addresses, while W3C develops web standards. Network operators and regulators influence deployment and policy.

The Internet has transformed communication, commerce, education, and culture, but also raises concerns about privacy, security, and digital inclusion. cybersecurity, data protection, surveillance, and questions about net neutrality and access inequality are ongoing policy and technical challenges.