Screws look an awful lot like nails, but their key differentiating characteristic is their ridges, uniquely shaped heads, and the tools used to drive them. Screws are used either with a screwdriver or with a drill, depending on the project. Screwdrivers are typically used for screwing screws into pre-made holes, such as in assembling furniture, whereas drills are used to directly insert the screw through wood or other materials.
The ridges around the cylinder are called threads, and they help secure the screw. The head of the screw comes in different designs depending on its driving instrument to ensure it can distribute the force effectively. The smooth area right below the head on some screws is called the shank. Screws can be made of many different materials such as stainless steel and aluminum, and they can be coated to promote durability and longevity.