MacOS High Sierra
macOS High Sierra is the fourteenth major release of macOS, Apple Inc.'s desktop operating system for Macintosh computers. macOS High Sierra was announced at the WWDC 2017 on June 5, 2017 and was released on September 25, 2017. The name "High Sierra" refers to the High Sierra region in California. Like with Snow Leopard, Lion, Mountain Lion, Mavericks, Yosemite, El Capitan and Sierra, the name also alludes to its status as a refinement of its predecessor, focused on performance improvements and technical updates rather than user features. Among the apps with notable changes are Photos and Safari.