What is VPN (Virtual Private Network)
A logically defined network where data flows through a tunnel between two sites and where the data might be encrypted, allowing the data to be securely sent across an untrusted network (eg. the Internet). VPN comes into two major styles:
1. Site to Site VPN
There is no need of client and VPN software to connect to the VPN. When the destination is for remote site VPN end, the data will be encrypted in the router.
2. Remote Access VPN
This type of VPN is for connecting to the office for the users from home i.e. laptop or anywhere in the world. Remote access client software is usually but not always installed on a PC for authentication, SSL (secure socket layer).