What are the reasons for putting setting up a VPN?
Does it require a domain name?
The difference with VPN is you "become" a member on the remote network. Your local IP is in the same scheme @ the remote end and you have access to all machines (based on your VPN config).
So if you require access to your Domain Controller / File Servers / Desktop machine, it's like you're physically at the office vs. just shelled into one machine. This means that if you need to run an application that requires resources @ work you can do it.
It works great for laptops, when you're @ work you log in normally, when you're @ home you VPN in and all your custom software works (although slower) as if you were there.
VPNs allow you to access a network from a remote location using an encrypted tunnel over the internet. Once you connect your computer to a VPN you can access everything you could if you were connected directly to the network.
Contrast this with most "remote control" applications:
Both are susceptible to connection interruptions but a VPN is a little more resilient because you can work with files from your computer rather than from a remote computer.
VPN's don't require a domain name. You can set one up using only an IP address. A domain sometimes makes it easier because you don't have to remember a string of numbers.
In many cases you can use both remote control software and a vpn. If you want to tinker with both you can try out logmein.com. They have free examples of both that are very easy to setup.