A snowboard is very similar to a surfboard, but it's for standing on and sliding down a snowy mountain. If you visit a ski resort, you'll see many people zipping down the slopes on snowboards.
The equipment that you use for surfing down snow-covered hills is called a snowboard, and you can also use the word as a verb: many teenagers love to snowboard during the winter. Snowboarders usually wear helmets and strap their snowboards to their boots. They often fly down mountains alongside skiers, and they tend to fall down much more often. Snowboards, along with the word itself, became popular in the 1980's.