A prune is a dried plum, most commonly from the European plum tree. Not all plum species or varieties can be dried into prunes. A prune is the firm-fleshed fruit (plum) of Prunus domestica varieties that have a high soluble solids content, and do not ferment during drying. Use of the term "prune" for fresh plums is obsolete except when applied to varieties of plum grown for drying.

A plum is a fruit of some species in Prunus subg. Prunus. Dried plums are most often called prunes, though in the United States they may be just labeled as 'dried plums', especially during the 21st century.