Pantomime is communication by means of gesture and facial expression. It may be applied to storytelling, dance and plays.
Sometimes we cannot express an idea in verbal language. Maybe it is an intense emotional feeling. Maybe the two parties do not share a common language. The ability to make gestures and movements with our bodies, along with our facial expressions is an important common ability in humans.
Because many actions (smiling, crying, pointing) are common for the same reasons for all humans, pantomime is a way to convey meaning (communication) to another person without using words.
Acting out motions of common activities are recognized by everyone, so things like pound with a hammer, pulling a rope, rowing a boat, mopping a floor, and just about anything else can be expressed and understood without knowing the particular words for them.