macOS High Sierra 10.13 was releasedin September 2017 with new features and under-the-hood enhancements that make your Mac faster and more reliable while laying the foundation for future macOS innovation.
Here’s everything new, improved and fixed in macOS High Sierra 10.13.

macOS High Sierra 10.13 release notes
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:
Improve your browsing experience with Safari:
Enjoy refinements in Mail:
Look up flight information in Spotlight:
Collect your thoughts with Notes:
Capture a moment in FaceTime:
Get music suggestions from a more natural-sounding Siri:
Universal Clipboard
Copy and paste files from one Mac to another with Universal Clipboard:
Safely store your family data in iCloud:
iCloud Drive
Work together with iCloud Drive:
Apple File System
Upgrade the performance, reliability and security of your Mac with the new Apple File System:
Step up to the new standard for 4K video—HEVC:
Enjoy next-generation graphics and computation with Metal 2:
Apple File System requires all-flash internal storage. Playback of 4K HEVC video requires a Mac running a sixth‑generation Intel Core chip or newer.
Some features may not be available in all regions or all languages and some of the features require an iCloud storage plan or have specific hardware requirements.
For the full list of features supported across different Mac models,check out Apple’s official macOS Feature Availability webpage. For the security content of macOS High Sierra,see Apple’s support document.
Installing macOS High Sierra
To install macOS High Sierra on compatible Macs running an older macOS release, use the standard Software Update mechanism: choose App Store from the Apple menu, then click the Updates tab to grab the software.
If you plan on upgrading multiple Macs, it may be a good idea to create a USB installer.
TUTORIAL:How to create a macOS High Sierra USB installer
With the USB installer, the operating system can be deployed on multiple Macs without having to redownload the software update separately on every Mac you own. You can also boot from the USB installer by holding theOption (⌥)key whilst starting up your Mac.