macOS High Sierra is an operating system developed by Apple Inc. for its line of Mac computers. Released in September 2017, it introduced several enhancements, including improved performance and storage management features. One notable addition is the Apple File System (APFS), which optimizes how data is stored and accessed. High Sierra also brought updates to key applications like Safari, which features improved privacy settings, and Photos, which offers better editing tools. The system supports virtual reality and enhanced graphics capabilities, making it suitable for creative professionals and gamers alike. Overall, it focuses on refining user experience and system efficiency.