The sprint is a race between two riders over three laps of the track.
The two riders start side by side, and on the starting signal set off, usually very slowly, before building up to a full-on sprint finish. It is an extremely tactical event, with some riders not wanting to be in the front for the full race, which is why they may slow down and use the full width of the track.
The event starts with a 200m time trial to determine the rankings for the 16 riders in the first round. From then on the competition is a knockout, going to quarter-finals, semi-finals and the final, which are all the best of three heats.
For a complete set of rules, please refer to the website of the International Cycling Union (UCI), governing body for the sport.