Olives are classified as a fruit. Olives are from the genus Olea and the species europa. The genus Olea contains approximately 20 species. Only one species in this genus, europa, produces edible olives and the oil consumed from these olives.
Canned olives come in two distinct types: ripe and green ripe. Ripe olives have been treated and oxidized to produce a dark brown to black color. Green ripe olives are those that have not been oxidized in processing and come in various shades of green. Olive were originally brought from southern Europe to the United States via Mexico in the 18th century. As of September 2014, California is the only U.S. state to produce olives commercially.