A roll can be served and eaten whole or cut transversely and dressed with filling between the two halves.
Rolls are also commonly used to make sandwiches similar to those produced using slices of bread.
Though they come in many shapes and sizes, they are most commonly hand-sized or smaller, with a round top and flat bottom.
The different terms originated from bakers, who labelled different bread rolls depending on how they made the dough and how they were cooked.
Over time, most people have come to use one name to refer to all similar products regardless of whether or not it is technically correct by the old terms.