Drywall screw is always used for fastening sheets of drywall to wall studs or ceiling joists.
Compared to regular screws, drywall screws have the deeper threads.
This helps prevent the screws from being dislodged easily from the drywall.
Drywall screws are made of steel.
In order to drill them into the drywall, a power screwdriver is needed.
Sometimes plastic anchors are used together with drywall screw. They help balance the weight of a hung object evenly over the surface.