Deep focus, Shallow focus or Bokeh
Deep focus is a photographic or cinematic technique where all the elements in the frame are sharp or in focus. This effect can be achieved using a large depth of field or small aperture. In this kind of images the foreground, middle-ground and background are all in focus and is achieved with the use of a hyperfocal distance of the lens.
Shallow focus is a photographic and cinematographic technique where one plane of an image is in focus while the rest is out of focus. It is usually achieved using a small depth of field or large aperture. This is used to emphasize the importance of the character or subject placed in the image.
Bokeh is a Japanese word which means “blur”. Though the technical result of shallow focus and bokeh is of same but the word bokeh defines the term more technically, which means the aesthetic quality of the blur. The main reason for the blur is the lens and its quality defines the result of it. Therefore the differences in lens aberrations, aperture, lens design and some other factors results in good or bad bokeh.