A sausage is ground meat, usually pork, beef, chicken, or another protein stuffed into cases or the animal intestines.
The meat is seasoned before stuffing takes place. Italian sausage, on the other hand, is unique. It is the same process, but Italian sausage contains more than salt, pepper, and garlic. It has additional spices, including fennel seed and anise seed.
Italian sausage is of two types – sweet and hot. The sweet sausage omits peppers, while the hot variety has all spices complete. These two sausages can be used interchangeably according to your spice tolerance and the dish you are making.