Calzone, meaning stocking or trouser in Italian, originated in Naples in the 18th century. One theory is they were named this because they were easy to eat for travelers, who might be wearing stockings or trousers. In Italy, sandwich-sized calzones are served at lunch counters and by street vendors because they are easy to eat while standing and walking. Usually, they do not have tomato sauce inside; stromboli, an American invention, often has tomato sauce and is shaped in a cylinder. Calzones, often confused with stromboli, are in a half moon shape. Source - WikiPedia