VPN?… Yes… VPS is Virtual Private Network. The simple description is a secure connection between two parts of a private network that is used on a public network such as the Internet to reduce operational costs. for more information about what is VPN, and How VPN works?.. please watch this video
Virtual Private Networks [Cisco]
This is VPN descriptions by CISCO
What is VPN?
Virtual Private Networks, an Introduction
The other descriptions about VPN
How VPN Works?
Describe about how VPN Work
I hope this can help you to understand about What is VPN and How it Works.