A hot dog bun is a type of soft bun shaped specifically to contain a hot dog or frankfurter. The original purpose of this food was to make it possible to eat hot dogs without burning one’s hands.
There are two basic types: top-loading (also known as Frankfurter rolls) New England Style Rolls or Lobster Buns in some areas, and side-loading, common in the rest of the United States also called American Style Buns. The advantages to a top loader are that it holds the hot dog securely and fits nicely into little three-sided paper boxes. Top loaders are generally baked side by side and torn apart as needed, leaving a flat side surface for grilling.