Wood grain refers to the pattern that appears on the surface of wood, which is created by the growth rings of the tree. Different types of wood grain can be used in woodworking to enhance the aesthetic appearance of a piece. For instance, certain wood grains can highlight the natural beauty of the wood, while others can be manipulated to create intricate designs. Understanding wood grain is essential for artists and craftsmen as it influences both the visual appeal and the structural integrity of the final product.