10.13.6 is the most refined version of the original APFS rollout. It offers faster file copying, better disk space management, and crash protection without the bugs of earlier 10.13 releases.
Released on September 25, 2017, macOS High Sierra (version 10.13) represented a deliberate shift in Apple’s software philosophy. While many operating system updates prioritize "flashy" user-facing features, High Sierra focused on "under-the-hood" foundational technologies. The final stable release, version 10.13.6, marked the culmination of this cycle, offering a highly polished and efficient environment that set the stage for modern macOS innovations. How to download and install macOS - Apple Support download macos high sierra 10.13 6 dmg file