Directional: a kite board that usually looks like a windsurf board or surfboard that is intended to be ridden in one direction. It rides best in one direction and has definite nose and tail ends. Surfboards can be considered directionals. These can be ridden with or with out foot straps.
Depowering: changing the angle of attack (AOA) to release pressure and reduce pull. This can be accomplished by pushing out the the bar or pulling on the depower strap.
Downwind: the direction that the wind is going toward, opposite of upwind.
Drag: the resistance to movement.
Drift: the sideways movement due to the action of the wind on the kite.
Dual Line, 2 Line: Kite which is flown using 2 lines of equal length which enables the rider to steer the kite right or left. These kites have a fixed amount of power. Often, trainer kites are dual line.