Instead of making the player restart an entire level (or reload a checkpoint), some games allow the player to instantly pause and rewind the action they just did, even if it is only a few seconds of time. This allows players easy access to immediate trial and error during specific sections of a game, and presumably lowers frustration levels by not making the player start over from the beginning.
It has become more and more popular in racing games, with the developer Codemasters using this feature in virtually all their games since DiRT. It has also become a staple in the Forza franchise. It has been used in several puzzle games; of note is the game Braid, where the rewind feature is used extensively, not only for trial and error, but also as a puzzle solving mechanic.