Image Retention vs. Burn-In

Image Retention vs. Burn-In

Image retention is a common effect that you might have seen after turning off a CRT television at night: the last image to appear on the screen stays there for a while after the TV is off, then fades away slowly. This is caused by a charge build-up in the phosphors (the glowing picture elements in the screen), and will go away after the display has been powered off for a little while.
Burn-in, on the other hand, is permanent.

Since it is caused by uneven aging of the screen phosphors, the "burned" image will persist forever, like a tattoo. It can be caused by spending a lot of time watching stuff in a 4:3 (non-widescreen) aspect ratio, watching a news channel with a stationary "news ticker", or playing a game with stationary screen elements.

Just as a tattoo can be removed with a great deal of effort, there are ways to fix a burned-in screen. But an ounce of prevention is worth a pound of cure: follow a break-in procedure when the set is new.