Spaghetti alla Carbonara literally means "Spaghetti in the Manner of the Charcoal Maker". Some believe that the dish was once popular with Charcoal makers who lived on the Mountains near Rome because the ingredients were easily portable and cooking was fairly uncomplicated. Others believe the dish derives its name from all the freshly ground pepper that is added to the spaghetti at the last minute. Actually, the origin of the dish is quite recent, since it was unknown before Second World War.
The dish uses pancetta or guanciale, which are similar to bacon. If you want to stay true to the Roman heritage of the dish, you must use grated Pecorino Romano cheese, but it can be substituted by Parmesan. A mix of the two cheeses is also common.