An FPS monitor is a piece of software designed to display or record the frames per second (FPS) a computer screen is showing. These software packages are typically used to gauge performance of a computer system while gaming.
Some games, particularly online games, have built-in FPS monitors. Screen recording software such as that used to record live game action also typically has a built-in FPS monitor. FPS monitors can be used to gauge performance gains or losses while running additional software or making system changes. If the frames per second rate drops too low, the screen looks choppy and game-play may suffer as a result.