A penny is a coin (pl.: pennies) or a unit of currency (pl.: pence) in various countries. Borrowed from the Carolingian denarius (hence its former abbreviation d.), it is usually the smallest denomination within a currency system. At present, it is the formal name of the British penny (abbr. p) and the de facto name of the American one-cent coin (abbr. ¢) as well as the informal Irish designation of the 1 euro cent coin (abbr. c).
https://en.wikipedia.org/wiki/Penny