Squat is one of the three aspects of powerlifting sport, with the other two being bench press and deadlift. The sport has two major formats, equipped and u-equipped, based on whether competitors are allowed to use supportive equipment, like suits. Competitions are conducted for both men and women, with nine different weight classification for men and seven different weight classifications for women.
Each athlete get three attempts during a competition. There are several aspects for a squat attempt to qualify as valid, like paying heed to the referee's signals, where the bar is positioned in the shoulders, and the downward and upward movement pattern. After an athlete finishes an attempt, the referee declares if the attempt stands or is disqualified.
Since squat is not an independent competition by itself, but is rather a part of a group of two other events, winners are not decided just based on squat results. The maximum weight an athlete was able to squat successfully, is added to the maximum lifts from other two events to decide the winner.
There are several federations that govern the sport with over 100 countries being members of one or more of these federations. Each federation conducts several competitions, and there will be some minor variations in competitions based on which organization conducts the event.