Registering Red Hat Enterprise Linux Clients

I’m trying Registering Red Hat Enterprise 7 Linux Clients
I use Registering Clients with a Bootstrap Script?

Why do I need this operation to complete the registration?
Who can help me explain the meaning of the parameter value?
What do these mean ?

Those are the gpg keys used to sign the rpm’s, you need them added to the system so it verifies the rpm’s are valid.

@mai do we need to procure any additional license to patch RHEL using SUSE Manager

Already answered in your other thread but repeating for completion: yes, you need to get either a RHEL subscription from Red Hat, or an Expanded Support subscription from SUSE.