Inside A Camrea:With Important Words And Definisions.

Shutter-is released, the mirror moves out of the light path and the light shines directly onto the film.
Aperture- is a opening or hole through which light travels through.
Exposure-The total amount of light allowed to fall on the sensor wile the taking of a photograph .
The Depth Of Field (DOF)- is the portion of a scene that appears sharp in the photo.
The Focal Length-An Optical system is a measure of how strongly it converges (focuses) or diverges light.

i Think These Words Are Important.

Mirror-Ia an object with at least one polisged and therefore speculary reflective surface.

Parallax- which occurs when the viewfinder or viewing lens is separated from the taking lens.

SLR -used a front surfaced mirror in the optical path to direct the light from the lens via a viewing screen and pentaprism to the eyepiece.

Focal Plane Shutter-located in front of the film plane, which prevents the light from reaching the film even if the lens is removed, except when the shutter is actually released during the exposure