Understanding SharePoint Permissions

[@AnjuAravind-h6h]

Very well explained.

[@coachAiman]

how to restrict access to site collection for admins or site owners , for instance Audit Department Site contains sensitive data and info which should not be accessed on by Audit members , not even SharePoint site collection admin or farm admin or owner can access and view the contents , how to do that , for on premises SharePoint 2019 for instance?