“Depth of field is the area of acceptable sharpness in front of and behind the subject on which the lens is focused. It essentially refers to how blurry or sharp the area is around your subject. The camera’s aperture controls this blurriness and sharpness by adjusting the size of the opening in the lens.” – STUDIOBINDER
shallow focus – one part of the frame is in focus, the rest is out of focus. Can be used to isolate a subject.
deep focus – everything within the shot is in focus. fore-ground , middle-ground and background in focus.