There are two different events - mogul and aerial.
Mogul skiers race down a 27-degree slope over large uniform bumps called moguls.
The length of the run is between 230 and 270 metres with bumps up to 1.2m high.
Mogul scoring is a combination of judging jumps and bumps and speed.
In a good run, shoulders remain parallel to the finish line, turns should be quick and short, and skis should not leave the snow surface, except at pre-determined jumps.
To perform aerial manoeuvres, skiers hit two large jumps, placed one-third and two-thirds of the way down the run.
The moguls competition consists of a run down a bump-laden course with two jumps.
The Olympic format is a one-run elimination round followed by a one-run final.
The skier with the highest score in the final round wins.
In the aerial competition, athletes perform various combinations of flips and twists off snow-packed jumps as high as 4m (13 feet), with take-off angles as steep as 70 degrees.
Competitors are scored on air, form and the landing.
The Olympic aerial format consists of a two-jump elimination followed by a two-jump final.
The highest total score from the final is the winner.