The two words themselves mean almost the same thing, but here's the difference.. the root of Terrible is "Terror" and the root of "Awful" is "awe". you can say either one. "This burned food is awful. This burned food is terrible." Same meaning. They are roughly the same level of bad.

“terrible” means something that causes “terror”, “fear.” “awful” comes from “awe-full.” meaning it makes you full of awe, usually at how bad it is. this is why people sometimes say “God is great and terrible” in old books. the word now means “bad”.

Awful came from the meaning "full of awe", which you will note when you check the dictionary, means something like a feeling of reverence, respect, fear and amazement. Terrible originally meant something that inspired terror or great fear.