Snowboards come in many shapes and sizes. Each size and shape corresponds to the riders ability, style, and height. Most snowboards today feature an identical twin tip for easy freestyle riding and good freeride capabilities. There are other shapes such as Alpine; a one directional racing board, with very little flex.
Snowboards must be chosen according to riders height. The smaller the board the smaller the rider and vice versa. The average snowboard is 158cm, which will work for riders from 5'6" to 6'0".
This is a great example of the sowboard shape most people ride. (twin-tip, freestyle)
When choosing a snowboard the most important thing to keep in mind is where you will be spending your time on the hill. If you plan on keeping to the board park or rails, one will want a board which offers a substantial amount of flex, while offering a proper shape and binding layout. The average snowboarder has little concern with the specifics of a snowboard, such as: stance width, nose and tail length, etc. The average freeride board will suit the snowboard hobbyist while offering just enough to those throwing cab 7's at the park.