Skiing is the activity of gliding over snow using skis (originally wooden planks, now usually made from fiberglass or related composites), with metal edges, strapped to the feet with ski bindings. Originally used primarily for transportation, skiing evolved into a popular recreational and competitive activity during the 20th century.

Skiing probably evolved gradually from snowshoeing, Norwegian and originally was a practical way of getting quickly from place to place in snowy climates. Early forms of skiing resembled today's Nordic, or cross-country, style. Sondre Norheim is often called the "father of modern skiing". In the 19th century, Sondre Norheim invented bindings that enabled the skier to do turns while skiing down hills. This form of skiing was called Slalom (sla låm, Norwegian dialect expression for a difficult track) by Norheim and his contemporaries. This form of skiing is now referred to as Telemark or Telemark skiing. The invention of firmer bindings to anchor the skier's feet to the ski, likely by Austrian Matthias Zdarsky, enabled the skier to turn more effectively and led to the development of Alpine, or Downhill, skiing. Shortly thereafter, in the early 20th century, Austrian Hannes Schneider pioneered the idea of rotating the body to help steer the skis. Soon this Arlberg technique, named for his home region, spread around the world and helped make skiing a popular recreational activity.