An extranet is a network built on TCP/IP protocols, whose usage is meant to member of one organization with the member of one or more partner organizations. The technology for an extranet is similar to that of the global Internet. The difference is, on an extranet various type of authentication, access control, or encryption are used to maintain a degree of data privacy. For site-to-site communications on an extranet, virtual private networks (VPN) are commonly deployed.
Extranet compares also with intranet. Intranets are directed to members of a single organization. Extranets are directed to one or more partner organizations. The use of security tools is similar for intranets and extranets.