A Virtual Privat Network (VPN) is a virtual communication network that uses the infrastructure of a physical network to logically connect computer systems. This can be any of the network types introduced above, however, the internet is the most common transport medium. This connects nearly all computers worldwide and is available free of charge, as opposed to privately operated MANs or WANs. Data transfer takes place within a virtual tunnel, which is built between a VPN client and a VPN server.
If the public network is used as a transport medium, Virtual Private Networks are generally encrypted to ensure that data stays confidential. VPNs are utilized to link LANs over the internet or to enable remote access to a network or a single computer via public connection.
Source : IONOS
