"Skis come in all shapes and sizes. Alpine skis have a curved-up tip in the front, a waist in the middle, and a tail in the back. They are shaped a little bit like an hourglass. This is called 'side cut' and this shape helps the ski turn. The base of the ski is smooth, and when it's nicely waxed it will slide nice and easy. The edges of the ski are made of metal that can be sharpened so that it bites and carves the snow and the skier can turn and stop."