Olives are very popular, especially in the Mediterranean area. There are various types of olives. Green olives are the unripe green fruit of the olive tree. Unlike some fruits, once an olive is picked it will not ripen any further. On the tree, olives progress from light green to brownish green to brownish purple to reddish purple to deep purple and finally to black. When a recipe refers to a "ripe olive", they are meaning a black olive. The flavor of an olive is largely due to the curing or pickling used on the olive.