Apples vs Crabapples

General
6

I don’t get it, from what I read crab apples is what apples with smller fruits are called (I honestly hear about it for the first time https://ru.wikipedia.org/wiki/Кребы), like Malus baccata? But what will grow from a seed is what is called a wild-type apple, it will have big apples, but they will be pretty sour, it won’t look like species and hybrids with small fruits.