A cheesy sandwich is a type of sandwich that is made with melted cheese. It is usually made with two slices of bread and melted cheese in between. The cheese can be any type, such as cheddar, Swiss, or mozzarella. The sandwich can also be topped with other ingredients, such as tomatoes, onions, and lettuce. The term 'melts' is often used to describe this type of sandwich, as the cheese melts when heated.