Apple File System

Apple File System (APFS; not to be confused with Apple DOS file system) was released in 2017, with Developer Preview versions before that (which might not remain compatible with the final product). It is a new file system optimized for flash storage and planned on being used across the spectrum of Apple devices under iOS, OS X, tvOS, and watchOS.

Links

 * Apple File System Guide
 * Apple File System
 * APFS filesystem format (blog post)