Find the untracked slopes!
Backcountry skiing is when skiers head outside the ski resort boundaries to explore the mountains and find untracked slopes. Backcountry skiers seek solitude, freedom and the challenge of finding fresh unexplored snow.
What equipment is needed for backcountry skiing?
Backcountry skiing is normally done on touring skis (heavy or light), telemark skis or even alpine skis with special bindings that allow the heel to be released. It all depends on the terrain to be tackled (e.g. rolling hills, tree-skiing, steep slopes, cornices etc.) and the snow conditions (e.g. hard-packed, deep, icy, spring conditions etc.). Keen backcountry skiers are often into snow-camping, bringing tents and supplies for several days.
For the more advanced skier
Backcountry skiing is for the more advanced skier with lots of experience in the alpine environment. There's no ski patrol looking out for you so you really need to be self-sufficient and know what you are doing. A good way to start is to do a specialised course (via a suitable ski school) or to learn from other experienced backcountry skiers. For more details there is a lot of great information on the OZBC Australian Backcountry Skiing site.