Q.I Have A Question:
I have a question: on your website: https://www.gardeningknowhow.com/edible/fruits/apples/self-fruiting-apple-trees.htm#:~:text=Thisisbecausealmostall,usually. you mentioned: This is because almost all apple trees are dioecious, which means they need cross pollination from another plant in order to bear fruit. question: what makes you say “almost”?

Certified GKH Gardening Expert
She says "almost" because some varieties are purported to be self fruitful as she says in the article. Even so, you will get more fruit if you have different varieties of the same species.
https://www.gardeningknowhow.com/edible/fruits/apples/self-fruiting-apple-trees.htm