Whether hanging pictures or securing shelving to the wall, it is never recommended to simply use Wood Screws, because of the soft drywall compound. Over time, the screws will widen the hole they are in and back out or fall out, which is obviously not what we wish to happen. Using drywall anchors is a fast, safe, sure way to ensure that the screws will remain where they are for a long time to come.
Pocket screws are used with a boring machine that drills holes slanting horizontally through the face of wood. The “pocket” is the hole where the Machine Screw head fits. Normally, pocket screws have a small head to fit down inside the hole, but you can use Anchor Screw if you take a minute to size the end of the hole with a drill. You can adapt any drywall screw to be used as a pocket screw.
The walls of most buildings are lined with drywall, which is also called gypsum or sheet rock. Drywall is used instead of the old method of applying plaster directly to walls, and makes the job easier since wall and ceiling surfaces can be put up in flat sheets. You can install drywall with nails or screws, and the drywall surface is easily penetrated by fasteners. Whether you are hanging the drywall itself or hanging pictures on a finished wall, there is a certain method for putting Wood Screw into drywall.