The term mountaineering describes the sport of mountain climbing. While some scholars identify mountaineering-related activities as climbing (rock and ice) and trekking up mountains, others are also adding backpacking, hiking, skiing, via ferrata and wilderness activities, and still others state that mountaineering activities also include indoor climbing, sport climbing and bouldering. However most of the scholars, the term mountaineering understand as a climbing (which now refers to adventure climbing or sports climbing) and trekking (hill walking in ‘exotic’ places). 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.