This sport was originally introduced in 1936 with alpine acting as a blanket term for several different styles of Olympic skiing, including downhill, super G, giant slalom and slalom. The former two are considered speed events and the latter two are technical events.
Downhill is exhilarating to watch because it has the highest speeds and is therefore the most dangerous; participants have been known to travel up to 100 mph. Because of these speeds, this style requires an aerodynamic tuck position while the skier navigates turns, dips and jumps throughout the course.
Super G (super giant slalom), giant slalom and slalom are all very similar in that they require the athlete to maneuver between gates throughout the course. Super G, introduced to the Olympics in 1988, sees competitors reaching speeds of 80 mph and has the most distance between gates. Giant slalom and slalom have shorter distances between the gates and have slower speeds of roughly 50 mph and 25 mph, respectively. These latter two Olympic skiing styles are more technical and utilize great agility to make all of the intense turns.
Medals are also awarded in alpine skiing for a combined event that debuted in 2010; competitors do a combination of runs including both downhill and slaloms.
A previous version of this event was called "military patrol," but the modern day Biathlon was officially introduced in 1960. This competition has become iconic to the Winter Olympics due to imagery of cross-country skiers toting small bore rifles on their backs. The event requires cross-country skiers to maneuver around a standard track that's occasionally broken up by shooting ranges. At these ranges, athletes stop to shoot in both the prone and half standing positions. Punishments are distributed for any target left standing, which can either be in the form of a penalty loop or time added to their finish.
There are many different formats of this competition, including: individual, sprint, pursuit, mass start and relay. They are all equally fun to watch considering the dynamics of the sport.
Probably the most straightforward of all the categories, cross-country skiing has been in the games since 1924. There are two main styles of competition: classical, with skiers staying in the predetermined tracks; and freestyle, a much faster style with skating-like strides. These styles are then utilized in sprint competitions, combined pursuits and relays.
There's also an event called Nordic combined (also established in 1924) that involves cross-country skiing followed by ski jumps. This event has seen many subtle changes over the years and, as of the 2010 Olympics, has only been a men's event (with competitions in individual normal hill, individual large hill and team).