A sausage is a food made from ground meat, and, usually, salt, herbs, and spices.
Typically the sausage is formed in a casing traditionally made from intestine, but sometimes synthetic. Some sausages are cooked during processing and the casing may be removed afterwards.
Sausage making is a traditional food preservation technique. Sausages may be preserved by curing, drying, or smoking. (Source: Wikipedia)