SLR - Single Lens Reflex
Aperture is the size of the adjustable opening inside the lens which determines how much light passes through the lens to strike the image sensor. It is measured in f-stops.
Shutter Speed refers to the exposure time. It is measured in seconds.
ISO refers to how sensitive the image sensor is to Light. The lower the ISO number, the slower the speed.
White Balance controls the colour outcome of the pictures. All Light gives off a colour temperature which the camera analyzes and internally adjusts so that the colours of the picture are captured in their true form.
