aperture-he lens opening that allows more, or less light onto the sensor formed by a diaphragm inside the actual lens.
shutter-he physical device that opens and closes to let light from the scene strike the image sensor. Minicams use both electronic and mechanical shutters.
exposure- Amount of light that hits the image sensor of film controlled by the shutter speed and
depth of field-The range of items in focus in an image.
F-stop-Number indicating the size of the aperture.
focal length-A lens' angle of view. Such as Wide angle, standard or telephoto.
focusing- is the point where light rays originating from a point on the object converge.
viewfinder-  is what the photographer looks through to compose, and in many cases to focus, the picture.
shutter lag- s the delay between triggering the shutter and when the photograph is actually recorded.
auto focus- uses a sensor, a control system and a motor to focus fully automatic or on a manually selected point or area.