Bluegrassrivals

I ahve a question I was browsing around on youtube and seen that some of the videos on there have been taken off of a ps3 or 360 or ps2 and posted on youtube. i seen some were just recorded with a video camara but some were real good quality and looked just like you was playing the game. Any know how they transfered the footage of the game to there computer. I got an idea on video series I was gonna do just wonderign if some one could help me out?

well if you have a video card in your comp. then its run through it as its being played you record the entire game then edit it to upload what you want to you tube.