What is a potato considered?

Arohanui, I'm not exactly sure, but I think tomatoes are actually fruit.

I thought it was a root

Cookie Bean, the Spanish brought them to Europe from South America, were they originated. they became a food staple in Northern Europe once they realized they weren't poisonous.

Basic rule - if it has seeds, it is a fruit. No seeds - vegetable. Or if it grows above ground it is a fruit, below ground it is a vegetable. Not sure about lettuce, cabbage etc.

I thought it was a seed because it grows eyes and you plant it to get other potatoes

Spuds have so much carbohydrate that they once just manage to be a vegetable.

it's actually a night shade really, which it's plant is considered poisonous..