Skis
Alpine skis are designed for downhill travel and do not move well across flat ground or uphill climbs. They are wider and might be shaped like an hourglass, wider at the tips and tails than in the middle, depending on whether the skier is interested in making curved or skidding turns.
Cross-country skis are designed for flat or uphill travel. They are lighter than alpine skis and designed to glide across snow. Classic cross-country skis have a ribbed structure on their base, which catches snow when the ski is pushed backward to provide a solid footing from which the skier can push forward. Skating cross-country skis lack the ribbed base. Instead they have a smooth base that allows the skier to push diagonally on each ski, propelling him forward, similarly to the stride used in ice-skating.
Bindings
Alpine bindings connect the skier to his skis. Both the toe and the heel are attached to the top of the ski. The toe piece and heel piece of the binding might be separate or attached by a connecting piece of plastic or metal. Adjustments can be made to bindings that change the amount of pressure that is required to release a skier's foot from the ski. Weight, skill and the amount of pressure that will be put on the foot during skiing are all factors that determine what setting the bindings should be adjusted to.
Cross-country bindings are designed to hold only the toe of the skier. The freedom of the heel allows the skier to extend his leg out and back, a movement required for propulsion, while the ski remains parallel with the ground.
Boots
Alpine ski boots are made of hard plastic material and extend above the ankle and end somewhere on the calf. The design is meant to stabilize the ankle and provide the skier with more control over the ski. This is analogous to the stability that is gained from the stiff design of hockey ice skates, in comparison to the less stiff design of figure skates.
Cross-country ski boots are made of soft material that might
be reinforced by hard plastics, which maintain shape and structure. These boots are shorter than alpine boots, extending only a short distance above the ankle.
Poles
Alpine ski poles are made of a variety of material, with the purpose of reducing weight while maintaining strength. Most often ski poles are made of aluminum, carbon fiber or graphite. Composite materials such as graphite are increasingly common in ski pole construction. They are used for balance and timing, although they are also useful for travel across flat or uphill terrain.
Cross-country ski poles are made often made of carbon or graphite fibers. They are used to add power to the skiers stride. Pushing down and back on the typically taller pole increases the force that propels the skier forward.
