Wheel hop is the action of wheels bouncing and "hopping" as throttle is applied. Wheel hop is caused by several factors including, unequal half shafts, sloppy motor mounts, and chassis deflection.
Torque Steer is the action of the car pulling, sometimes dramatically, to one side while applying the throttle. This action is present in front wheel drive or all wheel drive vehicles. With awd vehicles, the process of torque steer is usually not felt by the driver and is absorbed by the differential or transfer case however this still reduces power put to the ground because of drive train loss. Torque steer, like wheel hop is largely caused by several factors including, unequal half shafts, soft motor mounts, and chassis deflection.