Backcountry skiing (US), also called off-piste (Europe) or out-of-area, is skiing in the backcountry on unmarked or unpatrolled areas either inside or outside a ski resort's boundaries. This contrasts with alpine skiing which is typically done on groomed trails benefiting from a ski patrol. Unlike ski touring, backcountry skiing can include the use of ski lifts including snowcats and helicopters. Recent improvements in equipment have increased the popularity of the sport.