aperture - is a hole or an opening through which light travels.
shutter - is a device that allows light to pass for a determined period of time.
exposure - is the total amount of light allowed to fall on the photographic medium (photographic film or image sensor
) during the process of taking a photograph.
depth of field - is the portion of a scene that appears acceptably sharp in the image.
F-stop - of an optical system expresses the diameter of the entrance pupil in terms of the focal length
of the lens.
focal length - of an optical system is a measure of how strongly the system converges (focuses) or diverges (defocuses) light