PCOS and PCO, what's the difference?

Anon • 16||Christian✝||🇮🇹+🇦🇱||Jesus❤️||
I've been told I have PCO not PCOS I just want to know what the difference is between them, are people with PCO infertile? Is there a diet I need to follow? I can't really find information on PCO, I can only find info on PCOS.