The camera

Visible spectrum- is the portion of the electromagnetic spectrum that is visible to (can be detected by) the human eye.

electromagnetic spectrum- is the range of all possible frequencies of electromagnetic radiation.

Parallax- is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. 

camera obscura- is an optical device that projects an image of its surroundings on a screen. 

aperture- is a hole or an opening through which light travels. More specifically, the aperture of an optical system is the opening that determines the cone angle of a bundle of rays that come to a focus in the image plane.

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 size of the aperture and the brightness of the scene controls the amount of light that enters the camera during a period of time, and the shutter controls the length of time that the light hits the recording surface.

depth of field- is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image.
 

F-stop- the f-number (sometimes called focal ratio, f-ratio, f-stop, or relative aperture) of an optical system is the ratio of the lens's focal length to the diameter of the entrance pupil. 

focal length- of an optical system is a measure of how strongly the system converges or diverges light.