What is backcountry skiing?
Backcountry skiing is skiing in the unmarked and ungroomed areas. In normal ski, people go to a ski resort and ski on the slopes marked and maintained by the ski resort. Backcountry ski may use ski lift, or other transportation methods to get to the top of the hill, but they don't follow the marked slope. Backcountry skiers usually bring special gear to avoid hazardous condition, such as avalanche or cliff.
Instruction: What is backcountry skiing?
Context: 
Response: Backcountry skiing is skiing in the unmarked and ungroomed areas. In normal ski, people go to a ski resort and ski on the slopes marked and maintained by the ski resort. Backcountry ski may use ski lift, or other transportation methods to get to the top of the hill, but they don't follow the marked slope. Backcountry skiers usually bring special gear to avoid hazardous condition, such as avalanche or cliff.