There are many different types of skiing you can do or compete in competitions for. Types include:
Slalom skiing- a competitve type of skiing where you have to weave through poles against another racer
Snowpark skiing- snowparks are popular places in resorts where skiers and snowboarders can ski on jumps and ramps to do tricks
Cross Country skiing- where you use a different type of ski to 'walk' along flat land
Assisted skiing- a seat attatched to a ski which people with disabilities can use to ski
There are two main types of techniques. The first image is mainly a begginners technique called snowplough where you spread apart your skis to slow down. The second picture shows a more advanced technique called parallel turning where your skis are parallel when turning.