What is a countersunk screw and how is it used in woodworking and construction projects?

A countersunk screw is a type of screw with a head that is designed to sit flush with the surface it is being screwed into. This helps create a smooth and even finish. In woodworking and construction projects, countersunk screws are commonly used to join two pieces of material together without leaving any protruding parts that could cause a hazard or interfere with the overall appearance of the project.