What are deck plugs?

A: Deck plugs are cylindrical pieces of wood that fill the countersunk holes where screws are holding the decking in place. Plugs are different from dowels as the grain is perpendicular to the diameter as opposed to parallel as dowels are. After the plugs are installed and sanded, the holes are relatively hidden because the wood plugs match the deck wood. Occasionally, plugs are installed with a contrasting wood instead. This application gives an almost marine look (like a ships deck) to the deck but must be precisely aligned because irregular lines really stand out.