Torque- 

Torque is the twisting or turning effort. The torque is equal to the product of the force and its perpendicular distance to the point of rotation. It may or may not result in motion. 

You applied torque to the nut tightening the bolt. You apply torque to the steering wheel while turning the car. A torque is required while turning the car wheels on the road. More torque is required when the car is going up on the slope. 

Torque is measured in N-m. 

A torque is applied to rotate the wheel.

If a 20 N force is applied on the shaft through a crank radius of 1/2 m to rotate a wheel, you would be applying 20*1/2=10 N-m of torque to the crank. You would be applying this torque regardless of whether or not the crank was turning; and so long as you continued to apply 20 N force to the crank handle.