In modern times, the prune is the dried version of the plum. Most prunes are made from the La Petite d'Agen variety of plum brought from France in 1856 by French horticulturist Louis Pellier.
A new movement by the prune industry is to market prunes as plum raisins or dried plums in hopes the new term will appeal more to younger people.
More About Plums and Prunes: Plum Storage and Selection
What are prunes? FAQ
Plum and Prune Equivalents, Measures, and Substitutions
Plum and Prune Legends - The Dr. Pepper® Connection
Plum Photo © 2006 Peggy Trowbridge Filippone