Depth of field

 Depth of field is the amount of the scene is in focus and there are different magnitudes of focus. There could be a scene where only the foreground is in focus where the background could be very out of focus. And theres a different variation of this where it could be switched where the foreground is blurred and the background is in focus. There could also be where the entire scene is in focus. And where none of the scene is in focus

Deep focus:

Deep focus, which requires a small aperture and lots of light, means that the foreground, middleground and background of the frame remain in focus. This shows the whole scene in equal focus and this could easily be used to show the enormity of the scene using this to show a spars and barren dessert or the skyline of a city both with equal effect. this can be typically used with a long shot or extreme longshot to show the scene and the characters surroundings