virtual private network (VPN)

A computer network that uses a public telecommunication infrastructure such as the Internet to provide remote offices or individual users with secure access to their organization’s network. It is established, at the application layer of the Open Systems Interconnection (OSI) model over an existing physical network.

VPNs aim to avoid expensive systems of owned or leased lines that can only be used by a single organization. A VPN typically does not include every node present on the physical network.