VPN
definice
https://csrc.nist.gov/glossary/term/virtual_private_network
rfc4949.txt
virtual private network (VPN)
(I) A restricted-use, logical (i.e., artificial or simulated) computer network that is constructed from the system resources of a relatively public, physical (i.e., real) network (e.g., the Internet), often by using encryption (located at hosts or gateways), and often by tunneling links of the virtual network across the real network. (See: tunnel.)