Mountaineering is the sport, hobby or profession of walking, hiking, backpacking and climbing mountains. In Europe it is also referred to as alpinism, while in the Americas the term refers to a particular style of mountain climbing, that involves a mixture of ice climbing, rock climbing, mixed climbing, and where the climbers carry all their loads with them at all times. In the Himalayan regions the style of mountaineering is Expedition. While mountaineering began as attempts to reach the highest point of unclimbed mountains, it has branched into specializations that address different aspects of the mountain and consists of three areas : rock-craft, snow-craft and skiing, depending on whether the route chosen is over rock, snow or ice. All require experience, athletic ability, and technical knowledge to maintain safety. The UIAA or Union Internationale des Associations d'Alpinisme is the world governing body in mountaineering and climbing, addressing issues like - Access, Medical, Mountain Protection, Safety, Youth and Ice Climbing.