We all call tomatoes, beans and peas "vegetables". We all know that is not strictly true, in botanical terms.
Is it a vegetable? Is it a fruit? Is it a berry?
Strictly speaking, the word "Vegetable" is not scientific, and has no place in the field (hur hur) of Botany. A vegetable is a vegetative part of a plant which sustains the plant, whereas a fruit (any kind) is the reproductive part of the plant.
Therefore the swollen, red Tomato (which some people like to eat) is indeed a fruit, but its roots, leaves and stems are vegetables. You can see why the term vegetable is not particularly good now, eh?
The actual labelling of non-fruiting or fruiting bodies in botany is very complicated and quite dull (to non botanists anyway).
It generally boils down to how the fruit develops, and where it develops from, together with number and spacing of seeds etc...
Words like Pome, Drupe, Pepo, Hesperidium, Epigynous berries, Accessory Fruits, Simple Fruits and True Berries make for a very confusing picture.
I certainly will not bore you with the details - just type any of those words into a decent online dictionary (botanical), and your head will explode. (There was a reason I concentrated on Zoology at University you know)!
For the record though, in purely botanical parlance:
Tomatos, Aubergines, Chilli Peppers, Grapes.
OTHER / FALSE BERRIES (Epigynous berries, Pepoes, Hesperidia etc...)
Avocados, Bananas, Pumpkins, Melons, Cucumbers, Citrus fruit, Blueberries, Strawberries.
Elderberries, Peaches, Olives, Plums, Cherries, Almonds, Coconuts, Sloes
DRUPELETS (an aggregation of)
Apples, Pears, Haws, Quincy, sorry... Quinces.
Very, very confusing stuff huh?
In case any clever dick wants to impress you with their botanical knowledge and comes out with the normal:
"The Banana is the berry of the Banana herb", you have my permission to correct them fully and state that:
"The Banana that you refer to is not actually a true berry, but actually the parthenocarpic, epigynous or false berry of the over-sized Banana herbaceous plant, belonging to the genus Musa, which has a large herbaceous growth habit with leaves that exhibit overlapping basal sheaths that form a pseudostem making some members appear to be woody trees. But you probably knew that anyway, eh?