How Invisibility Cloaks Work?

You get under it and you can't be seen. Really neat if you can get your hands on one. I lost mine when I was at Hogwarts, Filch took it from me and I never got it back. Now that I'm an Auror I'm going to go back and get it. HA HA HA. I may even take Mr. Flich's cat while I'm there.