What’s a VPN
Info From Wikipedia.
A virtual private network (VPN) is a computer network that is layered on top of an underlying computer network. The private nature of a VPN means that the data travelling over the VPN is not generally visible to, or is encapsulated from, the underlying network traffic. Similarly, the traffic within the VPN appears to the underlying network as just another traffic stream to be passed. A VPN connection can be envisioned as a “pipe within a pipe”, with the outer pipe being the underlying network connection.
The term VPN can be used to describe many different network configurations and protocols. As such, it can become complex when trying to generalise about the characteristics of a VPN. Some of the more common uses of VPNs are described below, along with more detail about the various classification schemes and VPN models.
More here :
http://en.wikipedia.org/wiki/Virtual_private_network
