The number of steps that the dynamic range is divided into as specified by the bit-depth of the analog to digital converter.

A method of creating color by combining red, green and blue lights. White is created by adding by adding all of these colors, each at maximum intensity. Black is created by a total absence of these co [..]

Analog to Digital Unit. A number that represents the CCD or CMOS sensor's digital output. The number of electrons in each ADU is determined by the system gain.