Aperture - The size of opening that lets light into the camera.
Depth of Field - The range of distance from the camera that is deemed to in-focus (or acceptably sharp). A shallow depth of field means that much of the image is out-of-focus.
Exposure - The level of brightness of an image.
F-stop - Measurement of aperture, shown as a fraction. f/2 is a relatively large aperture, f/16 is relatively small.
ISO - The sensitivity of a film or camera sensor to light. Lower ISO means less sensitivity (so the image is darker) but also less grain or noise in the image.
Metering - The action of a camera adjusting the exposure (brightness) level using ISO, aperture and/or shutter speed.
Shutter Speed - The duration that the camera sensor is exposed to light whilst taking an image.