Olives are small fruits that grow on olive trees (Olea europaea). 

They belong to a group of fruit called drupes, or stone fruits, and are related to mangoes, cherries, peaches, almonds, and pistachios. 
Olives are very high in vitamin E and other powerful antioxidants. 

Studies show that they are good for the heart and may protect against osteoporosis and cancer.
The healthy fats in olives are extracted to produce olive oil, one of the key components of the incredibly healthy Mediterranean diet. 

Olives are often enjoyed in salads, sandwiches, and tapenades. The average olive weighs about 3–5 grams.