Are donkys actually donkys or are they horses?

(My brother wants me to ask this)​

Donkeys have visibly longer ears, while horses tend to have longer faces. The hair making up donkeys' manes and tails is stiff and bristly, whereas horses' manes and tails have softer and more flowing hair. ... Donkeys' backs are flatter than horses' and more often than not cannot hold a saddle.

Donkeys are a separate species from horses. A mule, Matthews says, is a hybrid – half horse and half donkey. Donkeys evolved into their own species.