The honest answer is this: Salami (sliced salami), pepperoni (sliced spicy salami), and sausage (pre-cooked fennel-flavored uncased/crumbled pork sausage).
In the US, “sausage” tends to generically refer to uncured, fresh, or raw sausages, often really meaning “ground meat mixed with herbs and spices sometimes in a tube or casing (but not always).”
The honest answer is this: Salami (sliced salami), pepperoni (sliced spicy salami), and sausage (pre-cooked fennel-flavored uncased/crumbled pork sausage).
In the US, “sausage” tends to generically refer to uncured, fresh, or raw sausages, often really meaning “ground meat mixed with herbs and spices sometimes in a tube or casing (but not always).”
Americans came up with the word hot dog then decided sausage should now mostly mean loose ground pork.