Why do books compiled in the same place have different publishers?

This is normal, perhaps because these books are aimed at different readers! For example, the book edited by the same publisher is suitable for junior college students, while the other is an undergraduate! For example, if the same book is reprinted and typeset, the publishing house may also change! Their prices may also be different! The content may change! In terms of quality, it doesn't matter as long as it's not pirated!