Ring Of Death Xbox

What is and how do you fix the red ring of death (Xbox 360)?
Hey I’ve heard so much about this “ring of death” on the Xbox 360 I need to know what’s about. What is it and how you can prevent it?
The ring of death is three flashing red lights in the first, third, and fourth quadrants of the ring of light. The easiest way to prevent it is to place the console in an open space with plenty of room in the back.
The Death of My Xbox 360
Ring Of Death Xbox