A virtual private network client is a piece of software designed to connect a user to a network by establishing connections using tunneling protocols. VPNs can create secure connections across public networks such as the Internet.
VPNs require that both endpoints of the connection are authenticated, often using client software that verifies the connections using passwords, biometrics or other means of cryptology to secure the network. Data sent across the VPN is encrypted; the packets of information are encoded using a specific security algorithm that is decrypted once the information reaches the client on the other end. Typically a VPN is set up using software such as Cisco VPN Client or LogMeIn Hamachi.