There are two different styles of cross-country skiing: ski skating and classic skiing, which is also known as striding, diagonal or traditional. Classic skiing is planting one ski down and pushing it back in order to propel the other ski forward. For example, as you put your left ski down, you'll simultaneously use the pole in your right hand to help balance you and push you forward. When you push down and back with your right ski, your left pole will be put into action -- hence "diagonal." Despite this moniker, the resulting motion is a smooth forward glide.
This method will also enable you to perform a diagonal climb and ski uphill, using shorter strides and assuming a more vertical posture. Steeper hills may require using the herringbone technique in which the skis are arranged into a "V" shape and the skier walks uphill by planting the inside edge of the ski into the snow.
Ski skating utilizes a motion that resembles rollerblading or ice skating -- you push out with one ski while gliding ahead on the other, and the two skis are always pushing away from each other. If both skis stayed on the ground, you'd likely find yourself spread-eagled on the snow, but your one grounded ski maintains your forward motion.
Alpine skiers don't have a monopoly on downhill descent -- such drops are no problem for cross-country skiers as long as they utilize the telemark turn. This turn involves bending one leg behind the other, pointing the forward ski into the turn and pointing the tip of the rear ski into the side of the leading ski. This is a free-heeled method of making wide controlled turns as you descend a hill.
On slight hills, skiers may opt for a double-pole technique in which they hold their skis in a fixed position facing forward and use both poles simultaneously to reach ahead and pull themselves forward. On flat or slightly uphill terrain, you can combine the double-pole technique with alternating kicks.
Don't strap on your skis just yet. Keep reading to learn some helpful cross-country skiing tips.