macOS High Sierra (version 10.13) is the fourteenth major release of macOS, Apple Inc.’s desktop and server operating system for Macintosh computers. The successor to macOS Sierra was announced at WWDC 2017 on June 5, 2017.
The name “High Sierra” refers to the High Sierra region in California. As with Snow Leopard, Mountain Lion, and El Capitan, 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.
-  Formalized paraphrase
- iMac: late 2009 or newer.
- Late 2009 or newer MacBook and MacBook Retina
- MacBook Pro (Mid 2010 or later):
- MacBook Air (late 2010 or later):
- Mid-2010 or newer Mac Mini
- Mid-2010 or newer Mac Pro
HEVC hardware acceleration requires a Mac with a sixth-generation Intel processor or newer:
- iMac: late 2015, 27″ or newer, 2017: 21.5″ or newer
- MacBook Pro (early 2016 or later)
- Late 2016 or newer MacBook Pro
New technologies at the heart of the system make your Mac more reliable, capable, and responsive—and lay the foundation for future innovations. MacOS High Sierra also refines the features and apps you use every day. It’s macOS at its highest level yet.
Easily organize, edit, and view your photos in Photos.
- Make short videos from your live photos using the new Loop and Bounce effects.
- Easily locate and organize your content with the new sidebar.
- Conveniently access all of your editing tools in the redesigned Edit View.
- Fine-tune color and contrast in your photos with the new Curves and Selective Color tools.
- Access third-party apps directly from Photos and save the edited images back to your Photos library.
- Rediscover images from your library with new Memories themes, including pets, weddings, outdoor activities, and more.
- Create printed photo products and more using new third-party project extensions.
Improve your browsing experience with Safari.
- Stop web videos with audio from playing automatically.
- Prevent websites and ad networks from tracking your browsing with Intelligent Tracking Prevention.
- New settings for Reader, page zoom, content blockers, and more let you make your web browsing experience unique to each site.
Enjoy refinements in the mail.
- Instantly find the messages most relevant to your search using Top Hits.
- Use Split View when composing a new email on a full screen.
- Save space on your Mac with compressed messages.
Look up flight information in Spotlight.
- Check the status of a flight by typing the airline and flight number in the Spotlight search field.
Collect your thoughts with notes.
- Organize your information using configurable tables.
- Pin your favorite notes, so they’re always at the top of the list.
Capture a moment on FaceTime.
- Take a live photo during a video call to any supported Mac, iPhone, or iPad.
Get music suggestions from a more natural-sounding Siri.
- Hear more variations in intonation, emphasis, and tempo when Siri responds to you.
- Enjoy personalized music recommendations from Siri when you listen to Apple Music.
Copy and paste files from one Mac to another with the Universal Clipboard.
- Copy and paste files between your Macs using standard copy and paste commands.
- Share a single iCloud storage plan with your family and keep everyone’s data backed up and safely stored.
- Set up your family with a few clicks and add capabilities when needed.
Work together with iCloud Drive.
- Share and work on any file in iCloud Drive with other people, so it is always up to date with the latest edits.
Upgrade the performance, reliability, and security of your Mac with the new Apple File System.
- update to a new file system architecture designed for all-flash Macs.
- When you do things like make a copy of a file or find the size of a folder, you’ll be more responsive.
- Enjoy faster and more reliable backups.
- Protect your entire drive with built-in native encryption for greater security.
Step up to the new standard for 4K video: HEVC.
- High-Efficiency Video Coding (HEVC) allows you to create and watch high-resolution videos while using up to 40% less space without sacrificing quality.
Enjoy next-generation graphics and computation with Metal 2.
- Get the most out of the graphics capabilities of your Mac with the new and improved version of Metal.
- Discover immersive tools for content creation with support for virtual reality.
- Build state-of-the-art apps with features that accelerate common machine-learning functions.
Some features may not be available in all regions or in all languages. Some features require an iCloud storage plan. Some features have hardware requirements. The Apple File System requires all-flash internal storage.
What’s New in Version 10.13.6/17G65
It is updated with the final macOS High Sierra Mac App Store Installer Application.