Capitalization of Internet (versus internet) refers to the orthographic conventions for when the word should be capitalized. When referring to the global system of interconnected computer networks, the conventions have varied over time, and vary by publishers, authors, and regional preferences.
The Internet versus generic internets
The Internet standards community historically differentiated between an internet, as a short-form of an internetwork, and the Internet: treating the latter as a proper noun with a capital letter, and the former as a common noun with a lower-case first letter. An internet is any set of interconnected Internet Protocol (IP) networks. The distinction is evident in Request for Comments documents from the early 1980s, when the transition from the ARPANET, funded by the U.S. Department of Defense, to the Internet, with broad commercial support, was in progress, although it was not applied with complete uniformity.Another example from that period is IBM's TCP/IP Tutorial and Technical Overview from 1989...