A nail file is a small tool used to shape and smooth the edges of fingernails and toenails. It typically consists of a flat piece of material, often coated with an abrasive surface, which helps to grind down the nail's surface. Nail files come in various materials, including emery board, glass, and metal, each offering different levels of coarseness for specific nail care needs. Using a nail file can help prevent nail breakage and promote a neat appearance. Regular filing can also enhance the overall health of the nails by reducing snags and splits. Proper technique involves filing in one direction rather than a back-and-forth motion to minimize damage.