A screwdriver is a tool that works like a lever and is used for turning screws. Screwdrivers have handles made of plastic or wood and a shank made of steel that fits into a slot in the head of the screw. Generally screwdrivers are divided to three types of manual , Pneumatic and powered. Powered screwdrivers are divided to Corded and cordless. The head of the manual screwdrivers are consist of two most common shapes: Slot head screwdriver and Phillips-head Screwdriver
Slot head screwdriver that is consists of a flat blade that fits in the single slot of traditional screws. This type is most common and the oldest screwdriver. A Phillips head screwdriver has a four star point at the end. It fits into the cross-shaped screws. This kind of head allows a user to apply more torque than is possible with Slot head screwdriver.