Metallica's 1991 album's official title is Metallica, despite its nickname The Black Album.
The title is eponymous, meaning it uses the band's own name. The nickname developed because the cover is dominated by black, with a subtle snake and the band's logo rather than a colorful illustration or elaborate scene.
Calling the record The Black Album distinguishes it from the band itself in everyday conversation. It also separates the 1991 release from Metallica's earlier albums, including Kill 'Em All, Ride the Lightning, Master of Puppets, and ...And Justice for All.
The self-titled design was a deliberate visual contrast to the detailed artwork associated with some earlier Metallica releases. The album's minimal presentation became one of its most recognizable features, and the nickname became so widespread that many listeners use it as though it were the formal title.