Definition: A rotational or twisting force, torque is the force that causes things to turn or rotate. For RC cars and trucks, the torque is associated with the motor or engine and the drivetrain. An RC needs enough torque applied to the drivetrain to cause the axles and wheels to turn and move the weight of the RC. The more throttle applied to the RC, the more torque (force) is applied to the drivetrain, and the more the vehicle accelerates and the faster the RC goes -- to a point.
It's possible to have too much torque -- or at least more than the individual components of the drivetrain can handle. Too much torque could cause some plastic parts to bend or break under stress. Enough torque applied to the rear wheels of an RC can cause it to do a wheelie or even flip over. On a slippery surface, too much torque can cause the wheels to spin too fast, unable to gain traction, and make the RC harder to handle or spin out of control.
Pronunciation: tork