An avocado does possess a single seed just like a drupe and consists only of the endocarp’s fleshy layer. However, they are classified as a berry and not a drupe because the seed of an avocado has a fleshy endocarp, unlike the hard one of a drupe. Thus, though these avocados are usually prepared as a vegetable, it is still a biological fruit. Also, they are considered to be single-seeded berries coming from the families of bay laurel and cinnamon trees. However, they are much different from blueberries or blackberries. Also, as per some studies, they are very much like drupes.