diegetic sound - Sound whose source is visible on the screen or whose source is implied to be present by the action of the film:
voices of characters
sounds made by objects in the story
music represented as coming from instruments in the story space ( = source music) Diegetic sound is any sound presented as originated from source within the film's world

non-digetic sound- Sound whose source is neither visible on the screen nor has been implied to be present in the action:
narrator's commentary
sound effects which is added for the dramatic effect
mood music Non-diegetic sound is represented as coming from the a source outside story space.

internal diegetic sound- well i couldnt find anything on this but i found the best sound website in the world o yea i mean extra credit its so good