The word 'ski' is Norwegian. It originally meant 'a split piece of wood', which is exactly what the first skis were: long, thin planks strapped to your boots. Hunters used them to chase animals across the snow. Soldiers used them to deliver messages. Farmers used them to visit each other in winter.
There is a Norwegian saying: 'Norwegians are born with skis on their feet.' Many Norwegian children learn to ski before they learn to ride a bike. Schools run weekly ski lessons in winter. Some children even ski to school.
The most popular kind of skiing in Norway is cross-country - long, gliding skis across flat snow or up gentle hills, powered by your own legs. It is one of the toughest sports on Earth, because you have to keep going for hours. Norwegian children grow up doing it for fun.
Another famous Norwegian sport is the biathlon. It mixes cross-country skiing with target shooting. Skiers race fast across the snow, then have to stop, calm their breathing, and hit small targets. It tests speed AND steadiness. Norway is one of the best biathlon countries in the world.