Lift

In hydrodynamics terms, a force generated by an object moving through the water, wherein the force is roughly normal to the direction of motion.

Drag is the force that is in the direction opposite to the direction of motion.

If you think of an aircraft, the lift on a wing is usually thought of as directed up. In general, lift can be in any direction, including down. With paddles, lift is a part of what generates the total thrust and is directed roughly normal to the direction of motion of the paddle blade.

If you look at a wing paddle, the stroke moves the blade out from the side of the kayak, generating lift in the forward direction. This lift propels the kayak forward. When a Greenland paddle is used with a canted stroke, the initial phase of the stoke generates lift with a forward component. This contributes to forward motion as well. Euro paddles can be used with some degree of a canted stroke, but if simply pulled back, the lift they generate is due primarily to vortices and is difficult to analyze.