What is the meaning of unbalanced force?

Unbalanced force occurs when two forces acting on an object are not equal in size, causing a change in motion. Unbalanced forces cause a still object to move or moving objects to slow down or speed up, stop or change direction.

A balanced force exists when opposing forces are of equal magnitude, ultimately canceling each other out and resulting in no motion. Unbalanced forces are not equal or opposite. When two unbalanced forces are exerted in opposite directions, the net force is equal to the difference between the two forces, resulting in motion in the direction of the larger force.