There are many types of hammers...
The common one is the claw hammer
Generally used for smashing nails and lifting nails. One side of the croissant has a relatively large curvature, which is convenient for picking up nails.
General products have limited durability and upper limit of force, and are not suitable for vigorous swinging.
The head of the geological hammer is relatively straight, and the blunt end is used for knocking and breaking rocks; the sharp end is used for directional crushing and stripping of rocks, which can also be used as picks and chisels...
Generally more durable.