macOS High Sierra was introduced at WWDC 2017 in June, but officially a new version of the operating system for Apple computers became available only on the night of September 26. The name of this update is in tune with the past, but in the High Sierra there are significant differences from just the Sierra.
Indeed, at first glance, there is nothing in the High Sierra that would give any radically new opportunities. The main external improvements relate to applications: first of all — «Photos» and Safari, the second — «Mail» and «Notes». The interface of the OS itself has not changed at all. However, from the very «foundation» macOS is one of the biggest updates, and for Apple, this is a big reserve for the future. The main thing: Apple has transferred its OS to a new file system — Apple File System (APFS) instead of HFS+.