Modern cross-country skiing is similar to the original form of skiing, from which all skiing disciplines evolved, including alpine skiing, ski jumping and Telemark skiing. Skiers propel themselves either by striding forward (classic style) or side-to-side in a skating motion (skate skiing), aided by arms pushing on ski poles against the snow. It is practised in regions with snow-covered landscapes, including Northern Europe, Canada, Russia, the United States, Australia and New Zealand. Competitive cross-country skiing is one of the Nordic skiing sports. Cross-country skiing and rifle marksmanship are the two components of biathlon, ski-orienteering is a form of cross-country skiing, which includes map navigation along snow trails and tracks.