Kiełbasa is Polish for traditional sausage.
The word has become a commonly used for Eastern European styles of sausage, including Ukrainian sausage, which is called kovbasa or kubasa.
The sausage in Poland is usually sold in two forms, fresh and dry. This version is for the fresh version which can be eaten cold or cooked. It's the fresh one that is used in traditional polish dishes, such as "Biały Barszcz" or "Bigos".