How many strings does a mandolin commonly have?

A mandolin is a stringed musical instrument in the lute family and is usually plucked with a plectrum. It commonly has four courses of doubled metal strings tuned in unison (8 strings), although five (10 strings) and six (12 strings) course versions also exist.

Mandolins evolved from lute family instruments in Europe. Predecessors include the gittern and mandore or mandola in Italy during the 17th and 18th centuries. There were a variety of regional variants, but two that were widespread included the Neapolitan mandolin and the Lombardic mandolin. The Neapolitan style has spread worldwide.