Wood screws have always been the superior way to fasten wood to wood. There are different designs for hardwood, softwood, exterior and interior applications. There are precise lengths for delicate wood joinery, and they are easy to control. If there is a choice between screws and nails, it's almost always beneficial to use screws on any woodworking project.
Due to the way threads bury themselves in wood, they can actually be used instead of clamps. Threads bite into the wood, creating torque between the head of the screw and the two pieces of wood being joined together. If the wood has a warp, or gap that won't come together, screws will pull the wood together with force. If glue is added to the two pieces of wood before the screw is applied, a permanent bond will form, with the screw acting as a permanent clamp.
One overlooked benefit of screws---they are removable. In restoring, repairing, or if you realise that you have made a mistake, and need to take a step backward, the fact that you can remove a screw is priceless. For dismantling a deck, furniture or any woodworking project, if it has screws, they can be removed.
Easy to Use
Wood screws are easy to apply. They have a very sharp tip that initiates and penetrates the wood easily. You can pinpoint their location and with most building applications, you can use a wood screw without drilling a pilot hole. If you do need to drill a pilot hole in hardwood applications, you can pre-drill and put a screw in from any angle, upside down, sideways, or in places that are very tight and inaccessible. Wood screws are also faster than nails.
Inexpensive and Versatile
Wood screws are relatively inexpensive. For one reason, you don't need as many screws as nails for the same application. You can get specialised screws for particleboard, hard or soft wood, in any length. Wood screws are available in hardened steel varieties in different colours such as antique brass, and you can also buy them treated for outdoor use to repel rust.
Wood screws are stronger than nails. In areas where stress from wind, weight or heavy traffic occur, the shear strength of screws makes them superior. Nails can break, bend or shear off. Screws have a much higher tensile strength, and won't loosen like nails. If a screw does happen to become loose for any reason, it can be tightened back up again.