
Virtual private network (VPN) is the term generally used to describe a communication network. The network that secure a connection network by using combination of various technologies tunneled through an otherwise untrusted or unsecured network. The operating principle of a virtual private network revolves around the fact that rather than using a specifically dedicated connection, a virtual network is established between geographically scattered networks and end-users over a public shared network, such as the Internet. In VPN software system, data is transmitted as if it were passing through private connections. VPN, by forming a virtual communication network, isolates the private network and hence the system is much less likely to be attacked from the outside world. The VPN network, feature independent choice of communication network selection. Using VPN software, a user can choose an independent internet protocol (IP) address space. Additionally, VPN software is being useful for unblocking of websites, bypassing restrictions and local blackouts, and streaming live events. In such ways, VPN software improves the network security and scalability.