Frames per second (FPS) is a measurement used for measuring display device performance in video capture, playback, and video games. FPS is a typical metric used in video capture and playback for analyzing video quality because it measures frame rate (the number of images presented sequentially per second). The human brain can only process approximately 10 to 12 FPS. Frame rates beyond this threshold are believed to be in motion. The higher the frame rate, the smoother the video motion seems. Full-motion video is typically 24 FPS or higher. Different video formats have varying frame rates. Slower frame rates result in smaller computer files. 

MobileMysterious Explanation:

Early silent films have frame rates ranging from 16 to 24 FPS. Because the cameras were hand-cranked, the frame rate fluctuated greatly. Filmmakers used this variety to their advantage, slowing or speeding the frame rate to communicate mood. Although the frame rate of these early films was sufficient to detect motion, the visual remained choppy. To reduce flickering, projectors used dual- and triple-blade shutters, which showed each frame twice or three times. This would raise the flickering to 48 to 72 hertz, making it gentler on the eyes. When sound film became available, new videos continued to use 24 frames per second with two or three-blade shutters.

The concept of frame rate remained mostly unchanged until the development of television. Television frame rates were determined by the frequency of power from a cable wall socket. In North America, Japan, and Korea, it was 60 Hertz, while most of the rest of the globe had 50 Hertz. This gave the televisions frame rates of 60 and 50 FPS, respectively. Neither format performs adequately at 24 FPS. Videos created for 60 FPS screens need 30 FPS, while 50 FPS televisions use 25 FPS videos. Each frame is shown twice to reduce flicker and adjust for the new speeds.