External Storage Global Credentials

Could anyone explain what the “Global Credentials” are for configuring external storage.
I’m using local storage and was wondering if I need to put my Nextcloud username and password into the global credentials area on the admin page. Also there are two different places to put global credentials: Admin -> External Storage, Personal -> External Storage

@LukasReschke added this here (and might be able to explain):

Thanks for the suggestion. After some more digging it looks like that global setting just provides you with an easy way to not have to enter the same password multiple times when setting up a lot of different external storage mounts.