What is the name of the sausage that is often used in a hot dog?

The sausage often used in a hot dog is called a frankfurter. The word comes from Frankfurt, Germany, where Frankfurter Würstchen developed as a thin, smoked sausage traditionally made from pork.

In American English, frankfurter, frank, and hot dog are often used interchangeably. Strictly speaking, a hot dog is the assembled dish—a sausage served in a partially sliced bun—while the frankfurter is one type of sausage used in that dish. Wiener, or Vienna sausage, is another closely related term.

The terminology varies by country. In Germany, the original Frankfurt sausage is distinguished from the pork-and-beef Vienna style, while in Austria sausages served in hot dogs are commonly called Frankfurter Würstel. Modern commercial hot dogs may use beef, pork, chicken, turkey, or combinations, so “frankfurter” describes the sausage tradition more precisely than one universal ingredient list.