2 Answers

See here.... http://compnetworking.about.com/od/vpn/tp/vpnsoftwarefree.htm

Virtual private networks (VPNs) are point-to-point connections across a private or public network.
There are two types of VPN connections:
1.Remote access VPN(Remote access VPN connections enable users working at home)
2.Site-to-site VPN(Site-to-site VPN connections enable organizations to have routed connections between separate offices or with other organizations over a public network while helping to maintain secure communications)
There are some real benefits from using proxy server(VPN):
1. You can hide the IP address of the client computer so that it can surf anonymous, this is mostly for security reasons.
2. You can scan outbound content and circumvent regional restrictions.
3. You can bypass security restrictions and filters (your work office have blocked facebook or something else, with proxy you can look at the blocked sites).
Personally i use VPN(Proxy) service for avoid ip ban while playing online game.
Then go to Ip-Details.com   before and after had VPN service,then compared the IP's.