A cheese grater is a kitchen tool designed to sliver or shred cheese easily. There are a variety of different styles, but most employ a network of sharp holes that the cheese is pushed over. A cheese grater is almost always made from metal, and they are available inexpensively at kitchen supply stores.
The differently sized holes on a cheese grater are used for specific cheeses. Very hard cheeses, such as parmesan or pecorino work best when used with the smallest holes. Medium-textured cheese, such as Monterey jack or cheddar, should be shredded using the larger holes. Semi-soft or soft cheeses should generally not be used with a grater, as they will simply smash against it and clog the holes.