The answer would be the static frictional force.
There are two basic types of friction: static and kinetic, where static means stationary and kinetic means in motion. When you first begin to push something, you’ll most likely realize that it won’t move without a strong enough force. Then, once you get it moving it requires less force to move it than what was required initially; this is the two frictional forces in action. Therefore, if you move your desk across the room, before it starts moving (meaning it’s initially stationary) you must overcome the static frictional force.
