What is a wood filler and how is it used in woodworking projects?

A wood filler is a substance used to fill in gaps, cracks, or holes in wood surfaces. It is typically made of a combination of wood particles and a binding agent, such as epoxy or latex. Wood fillers are applied to the damaged area, allowed to dry, and then sanded down to create a smooth and even surface. This helps to improve the appearance and durability of the wood, making it ready for finishing or painting in woodworking projects.