The Camera
Aperture - A space through which light passes in an optical or photographic instrument
Shutter - a device that allows light to pass for a determined period of time
Exposure - is the amount of light allowed to fall on each area unit of a photographic medium during the process of taking a photograph.
Depth of field - The distance between the nearest and the furthest objects that give an image judged to be in focus in a camera.
F-stop - the ratio of the lens's focal length to the diameter of the entrance pupil
Focal length - The distance between the center of a lens or curved mirror and its focus.
Obscura -  A darkened box with a convex lens or aperture for projecting the image of an external object onto a screen inside.
Plate Camera -  A camera designed to take glass plates but often adapted to take cut film.
Box Camera - a simple camera shaped like a rectangular box.
Rangefinder Camera - a camera fitted with a rangefinder: a range-finding focusing mechanism allowing the photographer to measure the subject distance and take photographs that are in sharp focus.

The back of the Cannon Rebel t3 has a number of buttons that do different things. There's a menu button that takes you to the menu.. a ISO button that adjust the iso of the camera.