Olive, just like a plum or a cherry, is a fruit.
Olive is a small, bitter-tasting fruit of the olive tree, Olea europea. As explained by Oxford Dictionaries, olives are classified as fruit because they’re formed from the ovary of the olive flower, and they’re seed-bearing structures, those small stones (or pits) that you leave on the side of your plate could grow into trees if you planted them.
In culinary terms, however, olives are like those other fruit, tomatoes, and are treated as a vegetable: we eat them in savoury dishes or on their own as a snack or hors d’oeuvre.
Olives can be picked when they’re unripe and green, or left to ripen on the tree, where their colour changes to purplish-black. Either way, they are too bitter to eat straight from the tree: they need to be treated first, usually by being soaked in brine.
Tip! Learn Olives Nutrition Facts and Health Benefits from Authority Nutrition.