There are varying online discussions about the difference between a calzone and a Stromboli.
And each have there ‘own story and are sticking to it’.
First, Stromboli is a place. It’s a small island in the Tyrrhenian Sea, off the north coast of Sicily; with a not completely dormant volcano. And It is an American invention from a famous Philadelphia pizza shop; apparently conceived to eat your pizza, ‘sandwich-style’.
And, calzone, or ‘pants leg’, like pizza, was born in Naples and meant for eating-out-of-hand while strolling. (Apparently, pizza was always eaten at the table with a knife and fork!)
The fillings being pretty much equal; it seems to be a question of shape. If your stuffed pizza is folded over and crescent- shaped, then it is a calzone. On the other hand, if you’re stuffed pizza is rolled and log-shaped, then it’s a Stromboli.
…And I won’t even get started on the sauce-inside or on-the-side debate.