i am studying at iiit campus,in india.i want to know about what is VPN and what is the use of that.so could you please tell me about that ?

Let us take an Example. We had an Office Microsoft in Hyderabad with a Network Name Called "MS Net". We had an another office called MS Dynamics in Chennai Called "MS Dynamics". MS Dynamics wants to give a project to Microsoft Company. But they Microsoft people has to work in MS Dynamics Company Network. Instead of travelling to Chennai Daily, user can connect to MS Dynamic Company of Chennai using Remote. This functionality can be acheived using VPN. "Connecting to other network from a remote Place" --> VPN