Frame rate, generally speaking, is how many frames of an animation are appearing on your screen per second. It is measured in frames per second (aka FPS). The term applies equally to film and video cameras, computer graphics, and motion capture systems.
For video frame rate, a low frame rate will create a flickering effect and makes video a bit choppy and strobe. However, a higher frame rate will make the video very large at a constant resolution, which is probably not accepted by most devices for playback. You know, a video with a higher frame rate may be refused and unplayable since some devices only accept a certain standard value of frame rate. Actually, there are some common-used main frame rate standards for video: 23.97 FPS, 24 FPS, 25 FPS, 29.97 FPS and 30 FPS.