Wiktionary
n. A form of relatively extreme skiing, often occurring away from traditional marked courses
Wikipedia
Freeskiing, or new school skiing is a specific type of skiing, which involves tricks, jumps, and terrain park features, such as rails, boxes, jibs, or other obstacles. This form of skiing resulted from a combination of the growth in popularity of snowboarding as well as the progression of Freestyle skiing. "Newschoolers", or those who specifically ski in this style, as opposed to traditional freestylers, freeriders, big mountain skiers, and racers, are often found in terrain parks, which are designed specifically for tricks.
Whether freeskiing is a subset of Freestyle skiing or not is a matter of controversy. Some participants view it as a separate sport and do not refer to it as freestyle. The sport does not require participants to compete, but there are competitive events available at every level of the sport. Currently there are two Olympic freeskiing events, half-pipe skiing and slopestyle. These events make up two of the four Olympic freestyle skiing events.
The sport has seen continual growth since its inception in the late 1990s. An entire industry has been created with this rapid popularization. As a result of this growth, there is currently a growing number of professional freeskiers. Most are highly competitive skiers, usually specializing in a certain freeskiing discipline. There are however professional skiers who do not compete, and rather produce and star in videos.