Camera Obscura- is an optical device that projects an image of its surroundings on a screen.

Electromagnetic Spectrum- is the range of all possible frequencies of electromagnetic radiation.

Film Frame- a film frame or video frame is one of the many still images which compose the complete moving picture.

Visible Spectrum- is the portion of the electromagnetic spectrum that is visible to the the human eye.

Light- light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight.

Camera Lens- a camera lens is an optical lens or assembly of lenses used in conjunction with a camera
body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.

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, for the purpose of exposing photographic film or a light-sensitive electronic sensor to light to capture a permanent image of a scene.

Exposure- is the total density of light allowed to fall on the photographic medium during the process of taking a photograph.

Depth of Field- is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an 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- is a measure of how strongly the system converges or diverges light.