The red ring is the three lights you get when your x-box screws over and never lets you play again (unless you restart a thousand times). It's caused by the overheating of the x-box.
The longer you play the hotter it get and it may be OK for a few weeks (or in some cases months) from playing to long but it would happen sooner or later. A lot of people regret it. My uncle does :3
Youtube 'Red Ring of Death'and you will see what I'm talking about.
RobThanatos
Just don't play it for more than 2 hours at a time or your 360 will fuck up with the red ring :3
dude117
what red ring?