Sausage is a food made from meat that's minced or ground, flavored with seasonings, and encased in a thin skin. It's best not to think too much about what lives inside a sausage casing; just enjoy eating it.
There are many kinds of sausage, some of which are sold raw, some cooked, and others smoked, cured, or dried. Traditionally, sausages have been a way to avoid waste, by using the less appealing parts of a butchered pig or cow, and a practical way to preserve meat so that it doesn't have to be cooked immediately or frozen. In the mid-fifteenth century, the word was spelled sawsyge, from a Latin root, salsus, or "salted."