A directional snowboard is designed to go in one direction better than the other. Some variations of a directional snowboard feature a fishtail, which is designed to maximise float in powder.
ALL MOUNTAIN SNOWBOARDS
All mountain snowboards are designed with piste riding in mind. But at usually the most versatile. They can be used for a variety of reasons, but feels more at home on the piste.
PARK / FREESTYLE SNOWBOARDS
Park / Freestyle snowboards are perfect for those looking to head to the snow park. They are easier to ride, allowing you to put more effort into tricks etc. Which also makes them good for beginners.
Splitboards are exactly that, boards that split. They split into 2 skis to allow you to hike to places not normally acceptable from lifts. When at the top simply clip the board together and ride down.