What is the fuction of field configurations and field configurations scheme?

Question

Based on the thread: https://community.atlassian.com/t5/Jira-questions/Re-Modifying-field-configuration-changes-the-default-fie/qaq-p/2315452/comment-id/891769#M891769

As we seen changes of one Field configuration reflects on all Field configurations i have, (even if Field configurations are in a separate Field configuration schemas) and affects all screens where the field is, and even if it's not on the screen. So I can't make exact field to be REQUIRED at one place, but OPTIONAL in other.

So what is the function for the field configurations and it's schemes then?

John Funk · Answer

In a nutshell, the Field Configuration will make the Field Required on Create for the Issue Types linked to the Field Configuration.

Mikael Sandberg · Answer

Here is a good overview of how the different schemes are linked to each other, https://confluence.atlassian.com/adminjiraserver/project-screens-schemes-and-fields-938847220.html

I know the KB is for DC, but the same thing applies in Cloud.