The purpose of the hammer:
A hammer is a tool that strikes an object to move or deform it. It is most commonly used to knock nails, correct or break objects. Hammers come in various forms, the common form is a handle and top.
One side of the top is flat for striking, and the other side is a hammer head. The shape of the hammer head can be like a horn or a wedge, and its function is to pull out nails. There is also a round head-shaped hammer head.