The internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide.

It is a network of networks that consists 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 protocol suite is the conceptual model and set of communications protocols used on the Internet and similar computer networks. It is commonly known as TCP/IP because the foundational protocols in the suite are the Transmission Control Protocol (TCP) and the Internet Protocol (IP).

The Internet is sometimes referred to as the network of networks because it is made up of millions of smaller domestic, academic, business, and governmental networks, which together carry various information and services, such as electronic mail, online chat, file transfer, and the World Wide Web.

The origins of the Internet date back to research commissioned by the United States federal government in the 1960s to build robust, fault-tolerant communication via computer networks. The primary precursor network, the Advanced Research Projects Agency Network (ARPANET), initially served as a backbone for interconnection of regional academic and military networks in the 1980s. The funding of the National Science Foundation Network as a successor to ARPANET in the 1980s marked the beginning of the transition to the commercial Internet we know today.

In 1989, the first direct IP connection between NSFNET and CSNET marked the beginning of the Internet, and commercial Internet service providers (ISPs) began to emerge in the very late 1980s. The NSFNET was decommissioned in 1995, replaced by the modern Internet infrastructure of commercial Internet exchange points, multi-provider Border Gateway Protocol (BGP) internet backbones, and residential broadband.