How do simple fruits, aggregate fruits, and multiple fruits differ?

Botanical classification of fruits is based on the number of ovaries and flowers involved in their development. The primary differences are as follows:

• Simple fruits: These develop from a single carpel or a compound ovary of an individual flower. They are the most common category and can be either fleshy (such as berries, drupes, and pomes) or dry (such as legumes and nuts).1
• Aggregate fruits: These consist of several separate carpels derived from a single flower (specifically, one apocarpous gynoecium). Examples include raspberries and blackberries, where many small drupelets are clumped together.12
• Multiple fruits: These represent a whole inflorescence, meaning they are formed from the gynoecia of more than one flower. Common examples of this type include the fig and pineapple.1

While these categories describe the origin of the fruit, some fruits are also classified as accessory fruits if they incorporate additional floral parts, such as the receptacle or hypanthium, into the mature structure.1