A few kinds

Frankfurter
Precooked smoked sausage, originally from Germany. Traditionally made from a fine pork paste, it is now found in several variations. The French version may contain beef and veal, while the North American version, the famous hot dog frankfurter, may contain mechanically separated meat, pork or beef by-products, as well as sweeteners, flavoring agents and additives. They contain up to 30% fat. 

Sausages from Strasbourg and Frankfurt are smoked and the casing may be removed before sale. 

Strasbourg, Alsace, Alsatian sausage, knack
The diameter varies from 16-28 mm.

Cocktail sausages
small, may be flavored, served with cocktails.

Cervelas
30 - 40 mm in diameter, usually found in 6-8 cm long portions. 

Vienna sausage
made from veal and pork. The diameter is between 16 and 28 mm. 

Bockwurst / Weisswurst

Bauernwurst

Bratwurst

Knackwurst

Wiener