In my experience in the US, frankfurters/weiners/hot dogs may be all beef, beef and pork, or beef, pork and turkey, always with a circular cross section and all within the same size range ~ just shorter than a hot dog bun ;^) While technically pre-cooked, they are normally steamed or grilled (or both) before serving.

Vienna Sausages, on the other hand, are musch smaller and generally available only in little cans, and normally eaten cold, without further cooking, and usually straight out of the container. Not exactly gourmet fare!