I don't have any experience with VPNs and was looking to understand how they work. Not technically but in practical use.

If someone needed access to a shared drive on a Windows server how is that done? Does the user have to connect manually to the VPN server each time? Is there software on the server, router?

Once connected to the VPN does the user connect to the whole network or just the shared drive?

As you can tell I have never played with VPNs so I am a bit confused by it all.