Snow skiing is a group of sports utilizing skis as primary equipment. Skis are used in conjunctions with boots that connect to the ski with use of a binding. Although snowboarding shares the general characteristics of skiing sports, it evolved from surfing and skateboarding and so is not considered a type of skiing.
Skiing can be grouped into two general categories. Nordic skiing is the oldest category and includes sport that evolved from skiing as done in Scandinavia. Nordic style bindings attach at the toes of the skier’s boots, but not at the heels. Alpine skiing includes sports that evolved from skiing as done in the Alps. Alpine bindings attach at both the toe and the heel of the skier’s boots. As with many disciplines, such as Telemark skiing, there is some crossover. However, binding style and history tend to dictate whether a style is considered Nordic or Alpine. Thus, in view of its lack of a locking heel, and its roots in Telemark, Norway, Telemark is generally considered a Nordic discipline.(wikipedia.org)