User Privileges

From what I saw in an earlier similar post from someone else 'wheel' is a special group that indicates that a user is an administrator and users of the wheel group aren't actually root but they can "take the wheel" for commands that need privileged access. –"Members of this group have permission to run installers, modify system preferences, etc. If you wanted to make special permissions for administrators, you'd assign them to 'wheel'.". I am still a bit confused , could someone explain?

Thanks.