Mirroring aarch64 repo

Hi folks, I am mirroring the Leap 15.4 aarch64 ISO and repo directories. I notice that the path ports/aarch64/distribution/leap/15.4/repo/oss contains directories/files for x86_64, s390x and ppc architectures. I am trying to understand what is the difference between the files in these two paths then — distribution/leap/15.4/repo/oss ports/aarch64/distribution/leap/15.4/repo/oss ... since both of them have aarch64 and the other architectures? Regards, Ish Sookun