What is the purpose of a chuck key for a drill and how is it used effectively?

A chuck key is used to tighten or loosen the chuck on a drill, which holds the drill bit in place. It is essential for securely fastening the drill bit so that it does not slip or fall out during use. To use it effectively, insert the chuck key into the chuck and turn it clockwise to tighten or counterclockwise to loosen. Make sure to remove the chuck key before turning on the drill to prevent injury.