The term 'Album Unit' can be broken down into two parts: CUT (3 letters) and PHOTO (5 letters). CUT is an abbreviation for Compact Disc, which is a type of optical disc used to store digital data. PHOTO is an abbreviation for Photograph, which is an image created by light falling on a photosensitive surface, usually photographic film or an electronic image sensor. Together, these two terms refer to a unit of physical media that contains photographs stored on a Compact Disc.