What are the rules of ski jumping?

Ski jumping is a sport in which skiers go down an inrun with a take-off ramp (the jump), attempting to go as far as possible. In addition to the length that skiers jump, judges give points for style. The skis used for ski jumping are wide and long (240 to 270 cm). Ski jumping is predominantly a winter sport, performed on snow, and is part of the Winter Olympic Games, but can also be performed in summer on artificial surfaces (porcelain or frost rail track on the inrun, plastic on the landing hill).