ZFS is completely different than XFS. XFS is like a better (different?) ext4. ZFS is an error-checking software raid COW filesystem that does snapshots and can have multiple replicas, both local and remote. It uses zvols and datastores. Think btrfs on steroids and with a working raid subsystem.
It’s got a weird semi-closed license because Oracle is involved but it’s never been enforced and at this point is in such widespread use in large and small enterprises that it would be impossible to enforce.