Alpine skiing, or downhill skiing, is the pastime of sliding down snow-covered slopes on skis with fixed-heel bindings, unlike other types of skiing (cross-country, Telemark, or ski jumping), which use skis with free-heel bindings. Whether for recreation or sport, it is typically practised at ski resorts, which provide such services as ski lifts, artificial snow making, snow grooming, restaurants, and ski patrol. "Off-piste" skiers—those skiing outside ski area boundaries—may employ snowmobiles, helicopters or snowcats to deliver them to the top of a slope. Back-country skiers may use specialized equipment with a free-heel mode for hiking up slopes and a locked-heel mode for descents. Alpine skiing has been an event at the Winter Olympic Games since 1936.