They are essentially the same fruit, picked at different stages of ripeness: unripe olives are green, black are fully ripe, and those with a violet tinge are picked sometime in-between. Black olives have a fruitier taste than the green and are more often used in cooking. Olives are one of the oldest processed foods known to man, and there are many regional varieties and preferences. In Spain, there are smooth, green table varieties, from large queen olives to the refined manzanilla often sold stoned and stuffed with red pepper, anchovy, orange rind or almonds. Purple-black Kalamata olives from Greece have an intense flavor, especially those allowed to ripen on the tree. The shiny Nicoise olives from Provence are small, black and wrinkled with an almost creamy taste and are often sold in jars. Kalamata and Nicoise olives are the ones most often used in cooking.
** Asian Recipes