The term mountaineering describes the sport of mountain climbing, including ski mountaineering. Hiking in the mountains can also be a simple form of mountaineering when it involves scrambling, or short stretches of the more basic grades of rock climbing, as well as crossing glaciers. While mountaineering began as attempts to reach the highest point of unclimbed big mountains it has branched into specializations that address different aspects of the mountain and consists of three (3) 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. Mountaineering is often called Alpinism, especially in European languages, which implies climbing with difficulty such high, and often snow and ice-covered mountains as the Alps. A mountaineer with such great skill is called an Alpinist. The word alpinism was born in the 19th century to refer to climbing for the purpose of enjoying climbing itself as a sport or recreation, distinct from merely climbing while hunting or as a religious pilgrimage that had been done generally at that time.