Is it relevant on which instance I have registered my account?

Hi all,

I am pretty new to lemmy and was wondering if it makes a difference where I register my account. On lemmy.ml the name „Green“ (this account) was available and on Lemmy.world „Green“ is not available anymore.

As far I understand Lemmy, it doesn’t matter, but I would be happy if someone could confirm or explain it to me. Kind regards.