Look at the most common hammer, the claw hammer. Practically every household has a claw hammer. it is used for pounding and extracting nails. One side is a flat and the other is shaped like a claw that is curved. The flat end allows you to pound nails into wood or walls while the claw end enables you to pull out nails from various objects. The handle of the claw hammer is made of wood, glass-fiber or steel.
Notice one of the heaviest hammers, the sledgehammer. This hammer weighs up to 14 pounds and will need two hands to sling it. It is used for heavy construction jobs such as knocking down drywall, concrete or brick. The head of the sledgehammer is made of metal while the handle is made of wood.
Search for a double faced hammer, the club hammer. This hammer has two sides that are flat that is used for light demolition work or hitting steel chisels or masonry nails. The handle of the club hammer is made of wood.
Recognize the hammers used by mostly engineers. The ball pein hammer has one end that is round and one that is flat. The round end is used to work with rivets and roves. The straight and cross pein hammers have one flat side, with the opposite being a wedge. The difference is the cross hammer has its wedge sideways while the straight is in line with the hammer. They are both used for various kinds of wood and metal work such as making cabinets or shaping metals.