An open global communication infrastructure consisting of interconnected computer networks that provide access to remote information and facilitate the exchange of information between computers. The global network includes governmental, academic, commercial, military, and corporate networks from around the world.
Originally, the Internet was developed for use by the United States military and later became a network widely used by academic and commercial organizations. Users operating on the Internet can read and download data on virtually any topic from around the world.
More formally, this is documented in the definition by the Federal Networking Council of the USA dated October 24, 1995: "The Internet is a global information system that is logically linked together by a globally unique address space based on the Internet Protocol (IP) or its subsequent extensions; is able to support communications using the Transmission Control Protocol/Internet Protocol (TCP/IP) suite, its subsequent extensions, or other IP-compatible protocols; and provides, uses, or makes accessible, either publicly or privately, high-level communication services."