A screwdriver is a hand tool used to turn screws, which are fasteners that hold objects together. It typically has a long, narrow shaft and a handle for gripping. The end of the shaft is shaped to fit into the head of a screw, allowing the user to either tighten or loosen it. There are various types of screwdrivers, including flathead and Phillips, each designed for different screw shapes. Screwdrivers are commonly made from metal for durability, with handles made from plastic or rubber for comfort. They are essential tools in construction, woodworking, and home repair, making them a staple in many toolboxes.