What is Remote Desktop?

Hey Guys,

So I was thinking about getting a Surface RT.I know that it can not run normal windows applications but I just read that its has some "Remote Desktop" app.Now I am not an overly tech savvy person and I have no idea what Remote Desktop is.But reading about it on the internet I saw that it allows you to run a regular windows application from your computer on your Surface.Is this true and how does this really work?I would appreciate it if someone could just clear this up for me.

Thanks