Frame Per Second means how many snapshots camera can capture the images, it is a tool to measure of how motion video is recorded, to make conclusion 25FPS is required to analyze data if event took place or not. In the motion picture industry uses 25 snap shots to create 1second video clip.
PAL: The standard used in India it delivers 25 FPS.
NTSC: The standard used in United States of America It delivers 30 FPS.
For e.g. take cricket match, there are several umpires are there 1st umpire can take decision in most of the case. The human eye and brain interface can process 10 to 12 FPS only, so some of the critical decision can’t be taken by himself, in such case he will escalate the case to 3rd umpire for decision making, video systems can process more than 25FPS so 3rd umpire able to judge our not out.