We won’t enumerate all the features and quirks of APFS here for more of that, read our High Sierra review and/or one ZFS developer’s in-depth notes on APFS’ key features. Aside from a handful of edge cases, the transition went without a hitch. If you installed the operating system on a Mac with an SSD, your filesystem was silently switched over from the decades-old HFS+ to something brand new. The Apple Filesystem, or APFS, was one of the biggest (though quietest) features included in High Sierra. APFS updates for hard drives and Fusion Drives
