ZFS is a file system focused on storage and redundancy. It's designed with file servers in mind, where high availability and data integrity are absolutely paramount. That's one reason it's interesting, but very exciting, to see it natively available on a desktop operating system like Ubuntu. Note that ZFS on Ubuntu is a new feature and therefore still flagged as "experimental."
This is a companion discussion topic for the original entry at https://linuxconfig.org/install-ubuntu-20-04-with-zfs