In the SQUAT, the athlete stands under a racked barbell which is loaded with weight. Grabbing the bar from behind, the bar is put onto the top of the back, resting on the trapezius. The athlete walks clear of the rack (unless competing in a federation using a "monolift", a device which supports the bar in place until the lifter is ready), and squats down until the upper leg at the hip joint is lower than the top of the knee. Although the bottom position is sometimes described as having the thigh "below parallel" to the floor, the top of the leg may not necessarily appear to be beneath parallel. The lifter then stands up again, and carefully returns the weight to the rack. Disqualification results from the bar making any downward movement after the lifter has started upwards, if the spotters touch the bar in any way, if the upper legs do not break parallel, or if the lifter makes no effort to rerack the weight under his own power.
In the BENCH PRESS, the athlete lies on a bench. A loaded barbell rests on stands built into the bench above the eye level of the lifter when lying supine on the bench. The athlete removes the bar from the supports with the aid of a "liftoff man", lowers it to the chest or upper abdomen and then presses it up to the full extension of the arms and carefully returns the weight to the rack. Disqualification results if the bar is placed too low on the body (varies by federation), if the bar does not rest on the chest before being lifted upward (in some federations, an explicit "press" command is given, and the athlete cannot lift upwards until it is given), if the bar fails to touch the chest, if the bar hits the uprights of the rack on the ascent, or if the bar makes any downward motion during the ascent. In addition, the lift is nullified if the feet move during the lift, if the buttocks lift off the bench, or if the body makes any extraneous movement during the lift.
In the DEADLIFT, a loaded barbell is placed on the floor. The athlete squats down and lifts the bar until the legs and back are straight, and the shoulders pulled back with chest proud. The bar is then returned to the floor in a controlled manner. In competition, the top of the movement is finished by 'locking out', which means to straighten the back and lock the knees into a balanced position. Disqualification results from the athlete failing to stand completely upright, for using the thighs to assist the lift (hitching).
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Organizations
Although powerlifting always uses the squat, bench press and deadlift as events, different federations have different rules and different interpretations of the rules, leading to a myriad of variations. Some federations, such as the ADAU and 100% Raw Federation, allow NO protective gear to be worn by the lifter. Some, such as the IPF and AAU, only allow a single-ply tight polyester squat suit, deadlift suit and bench shirt, wraps for knees and wrists, and a belt. Other federations, such as the IPA and WPO allow for: opened or closed back bench shirts, multi-ply gear, a wide awray of gear materials such as canvas, denim, polyester etc.
In an IPF bench press, the barbell can go as low as the xiphoid process and no further in the lift, whereas in other federations, the barbell can touch the abdomen. (This shortens the distance in which the barbell is moved and is an advantage to the lifter.)
With the advent of the latest high-tech gear, powerlifting gear usage has become somewhat controversial. For instance, equipment has enabled some gargantuan lifts such as Gene Rychlack's 1005 lb/456 kg bench press and Jeff Lewis's 1201.5 lb/540 kg squat. Yet some argue that allowing equipment that can give 220 lb/100 kg+ of assistance to the lift lessens the point of a purely limit strength sport. However, bench shirts help to prevent pectoral tears and shoulder injuries when lifting very heavy weights by removing much of the load stress from the pectorals and shoulders.
The multiplicity of federations and rules, the behind the scenes politics of Olympic certification, and the use and/or abuse of competition gear makes the inclusion of the sport in the Olympics unlikely. There is no recognition in the Olympics for powerlifting at this time. Powerlifting is, however, a part of the International World Games Association (IWGA)[1] which is patronized by the International Olympic Committee (IOC). The International Powerlifting Federation (IPF) runs worldwide events and aims to standardise an international competition, and is at the forefront of these kinds of efforts. The IOC recognizes the International Powerlifting Federation as the 'official' world powerlifting body, although other federations maintain a worldwide presence.

above is bodybuilding bench press, aim more at the pecs.

this is powerlifting benchpress, more tricep strength.
More pics soon