Kielbasa is a type of smoked sausage that originated in Poland. What sets it apart from other smoked sausages is its coarse texture and heady garlic flavor.
Smoked sausage, as compared to fresh sausage, is sold already cooked. The sausage is cooked and then smoked. And often, artificial smoke "flavors" are added as well. Because they're fully cooked, you can eat smoked sausages cold or warmed. In addition to kielbasa, other smoked sausages include Italian mortadella, Cajun andouille, German bratwurst, bologna and hot dogs. Smoked sausage can be made from ground pork, turkey, beef or a combination of meats -- and they can include any variation of seasonings.
Polish kielbasa is traditionally made from ground pork and, rarely, ground beef. Some commercial variations of kielbasa are made from ground turkey, but these aren't authentic. Garlic, along with pimentos and ground cloves, are the predominant seasonings.
Americans are less familiar with dry kielbasa, which is smoked and then dried to extend its shelf life. Dry kielbasa is usually served cold on a cheese tray, but has the characteristic garlic flavor of regular kielbasa. The drying process makes the flavor slightly more intense and the texture chewier and denser.
Any type of smoked sausage can be dried. Don't confuse dried smoked sausages with air-dried sausages such as Italian soppressata and French saucisson, though. Air-dried sausage is technically never subjected to heat, but cured with time and exposure to safe bacteria. In the United States, the Food and Drug Administration puts strict regulations on the production of air-dried sausage.