It's a tech device that captures what is on your screen and records it. That's how people make high quality gameplay videos. It literally takes the Audio/Visual feed from your console and records it.
If you don't want to shell out $40 for a (cheap) Capture Card, then your only other option would be to manually take a picture of your TV screen with a Camera of some sort, but it will never come out high quality. --- http://www.youtube.com/user/LigsGames