Skiing is a way of traveling over snow, using skis strapped to one's feet. In modern times it has been mostly an athletic activity. Skis are used in conjunction with boots that connect to the ski with use of a binding. Commonly, ski poles or "stocks" are used to improve balance and timing as well as for propulsion.

Skiing can be grouped into two general categories: Nordic and Alpine. Nordic skiing, the older of the two disciplines, originated in Scandinavia and uses free-heel bindings that attach at the toes of the skier's boots but not at the heels. Types of Nordic skiing include cross-country, ski jumping and Telemark. Alpine skiing (more often called "downhill skiing"), originated in the European Alps, and is characterized by fixed-heel bindings that attach at both the toe and the heel of the skier's boot.

The earliest people to ski may have been the distant ancestors of the modern day Sami. One of the early names used for the Sami was skridfinner/scricfinni/scritefinni/σκριϑίψινοι, which some have translated as "skiing Sami". Pre-historic Nordic people and Sami used skis to assist in hunting, military maneuvers, and as a practical means of transportation. The oldest and most accurately documented evidence of skiing origins is found in modern day Norway and Sweden. The earliest primitive carvings circa 5000 B.C. depict a skier with one pole, located in Rødøy in the Nordland region of Norway. The first primitive ski was found in a peat bog in Hoting, Sweden which dates back to 2500 or 4500 B.C. Joel Berglund reported in 2004 the discovery of a primitive ski, or "85cm long piece of wood", carbon tested by researchers in 1997 while excavating a Norse settlement near Nanortalik, Greenland. The primitive ski dated back to 1010, and is thought to be Greenland's oldest ski brought by Norsemen circa 980 A.D.