Screw driver is a tool for screwing and unscrewing screws.
How To Use A Screw Driver.
Hold the tip of the screwdriver with one hand as you turn its handle with the other. Grasp the handle with your dominant hand and the tip with your other as close to the head of the screw as you can. Apply enough force to turn the screwdriver clockwise to tighten the screw and the opposite direction to loosen it