Linda, This may be a bit difficult to understand. The other answers you were given by the others is not correct. This is NOT really a 'regional difference' The difference may be confusing sometimes. SANDWICH---- SUBMARINE... SANDWICH - A 'Sandwich' is a food item that contains varying amounts of parts of food within usually 2 pieces of bread or a roll. These various additions to the 'bread' part of the sandwich may be: meat, vegitables, even fruits. The shape of the 'standard' sandwich is square. SUBMARINE: The 'Submarine' is a large, metal/cast iron sea going vessel used by numerous navys/militaries throughout the world. These ocean vessels are usually used as a defense against other countries that may attack that particular country or their countries water continental waters. NOW if you take a 'Sandwich' which is usally in square shape, and you squish/squeeze the sandwich you can make the 'sandwich' take the shape of the 'Submarine' which would make the sandwich and submarine look/appear similar. Which leads to many peoples confusion about the difference. I will elaborate further on this in later forthcoming segments---- Thank you for your attendance to this posting! Jeff ----www.jeffriviera.us