A virtual private network (Virtual Private Network) is a private network that extends, through an encapsulation process and in some cases encryption, from data packets to different remote points.
The data packets of the private network travel through a defined tunnel in the public network.
Basically there are three VPN connection architectures:
Point to Point (Point to Point)
Remote access (Road Warrior)
Each architecture uses different combinations of protocols (IPSec, PPTP, L2TP, SSL / TLS or SSH) to guarantee the three fundamental characteristics: