Question: what is the difference between ground pork and breakfast sausage?
Answer: Pork sausage is ground pork that has been seasoned. You can substitute, but you'll have to bring your own seasoning. Pork is the word ascribed to the pig animal as a food product. We don't eat "pig" rather we eat "pork." Sausage is ground meat mixed with herbs and spices in some manner of form.