An emery board is a small, flat tool used for filing and shaping nails. It is typically made of a piece of cardboard or wood coated with a rough material, often made from crushed emery stone, which gives it its name. Emery boards come in various grits, allowing users to choose the right level of coarseness for their nail care needs. These boards are commonly used in manicures and pedicures to smooth out rough edges and shape the nails. They are portable and easy to use, making them a popular choice for both professional nail technicians and individuals at home.