The length of metal edge on the snowboards which touches the ground; it is the effective part which is used to make a turn. It does not include the edge of the tip and tail.

The difference between the two contact areas beneath the tip and tail when the camber is depressed. A measurement used to define the actual length of the surface area that comes into contact on a perfectly flat surface. [Go to source

The part of the snowboard edge that is in contact with the snow (on the side of the board), not including the tip and tail edges.