Force - Mechanics:
Sometime we push the wall, then there are no changes in position of wall, but no doubt we apply a force, as the applied force is not sufficient to move the wall, that is no motion is produced. So this is clear that a force may not produce necessarily a motion in a body.
The force is agency, which tends to change the state of rest or motion of a body, it is vector quantity.
A force is completely defined when the following four characteristics are specified- Magnitude, Point of application, Line of action and Direction of it.
OR:
The action of one body on another body can be defined as force. In mechanics, applied forces are divided in to two types: Tensile and compressive force.