Diegetic & Non Diegetic Sound

Here we have just researched about the two main types of sound that we use in future reference.
Diegetic Sound:
-Any sound, voice or piece of music that comes from within the world of the narrative.
-Sound or music that comes from something within a scene, such as a piano sound coming from a piano.
-Sound that other characters would be able to hear.  A song on a radio, for instance, as a character drives down the highway, would be a diegetic sound, as would someone coughing audibly during a scene. ...
sound generated within a film narrative.
-Music or sound effects that appear to eminate from the world of the film. This is in contrast to the music score for example, which accompanies the movie but clearly does not come from within it.
-Music, noise, and speech recorded from the event at the moment of filming; opposite of postsynchronization.

Non Diegetic Sound:

-Sounds, such as music or a narrator’s voices that come from outside the space of the narrative.

-Also called "commentary sound", it is sound which is represented as coming from a source outside the story space.
-Sound that the characters cannot hear and is not part of the imaginary world of the story. This includes a musical soundtrack or a voiceover (however this excludes a narration by a character within the story – referred to as an internal monologue and is diegetic).
- Sound which has a source neither visible on the screen nor implied in the action/ narrator's commentary (voice over) sound effects which are added for dramatic effect the score / mood music.

Both diegetic and non diegetic sound clip: