How do I remove chocolate and coffee stains?

A stain is a discoloration that distinguishes itself from the material on which it is found. It can be unintentional, in the case of domestic stains on fabric, cloth, or other material, or it can be intentional. Stains are used intentionally in a variety of fields, including research (biochemical staining), technology (metal staining?), and art (wood staining, stained glass.)