How can a tomato be a fruit? What is a fruit and what is a vegetable?
There are actually two answers. One classification is based on tradition and use and the other is based on science.
The popular definition of a fruit is a food that is sweet, juicy and usually eaten as a dessert. Vegetables can include roots (carrots), tubers (potatoes), stems (celery), leaves (lettuce), flowers (cauliflower), fruit (tomato) and seeds (corn). These definitions are based largely on custom, tradition and use - but they have little to do with science!
Botanical Definition - the one scientists care about
Botanically, a fruit is the ripened ovary of a flower, its contents and any of its related parts. Botanically, there isn't a classification for a vegetable. Therefore, many foods we think are vegetables are actually fruits!
Fruits include olives, tomatoes, squash, cashews, kernels of wheat, corn, rice and anything else growing from a plant's flower.
It gets even more interesting
Some plants are fruits, but not the kind you think they are...
Tomatoes, grapes, cucumbers, watermelons, oranges, lemons and even bananas are considered to be berries!
Berries that aren't berries....
Strawberries, raspberries and blackberries are not berries at all! They are called brambles! Brambles are actually aggregate compound fruits (think of a lot of tiny fruits all bunched together!)
Plants producing fruits with an inedible core such as apples and pears are called pomes. However, it is actually the core that is considered the fruit and not the part we eat!
Science is interesting and it can taste good!
(Source for this content: Various sources, including Myth Information)