A submarine sandwich, often called a sub or hoagie, is a type of sandwich made with a long roll of bread, typically filled with various ingredients. Common fillings include meats like ham, turkey, or salami, along with cheeses, vegetables, and condiments. The bread is usually soft on the inside and crusty on the outside, making it ideal for holding the fillings. Submarine sandwiches are popular in many regions, especially in the United States. They can be served cold or hot, depending on the ingredients and preparation method. Variations exist, such as the Italian sub or the meatball sub, catering to different tastes and preferences.