A flathead screwdriver is a hand tool used for turning screws with a straight, flat blade. The blade fits into the single horizontal slot on the head of a screw, allowing the user to apply torque to tighten or loosen it. Flathead screwdrivers come in various sizes, making them suitable for different screw types and applications. This tool is commonly found in households and workshops, often used for assembling furniture, repairing appliances, or performing general maintenance. The design of the flathead screwdriver is simple, making it easy to use for both professionals and DIY enthusiasts alike.