Note: Many topics at this site are reduced versions of the text in "The Encyclopedia of Networking and Telecommunications." Search results will not be as extensive as a search of the book's CD-ROM.

The term "extranet" is an outgrowth of "intranet," a term that describes internal networks that are built with Internet technologies such as TCP/IP, and Web protocols such as HTTP, HTML, and XML. Independent organizations that need to connect their networks together to securely exchange documents or engage in business transactions can do so by using the same Internet and Web technologies-thus the term "extranet." Extranets are cross-business connections built with private leased lines or encrypted Internet links that allow people and businesses to engage in secure business relationships.