Easily organize, edit and view your photos in Photos.

• Make short videos from your Live Photos using 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 colour and contrast in your photos with 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 video with audio from playing automatically.
• Prevent websites and ad networks from tracking your browsing with Intelligent Tracking Prevention.
• Customize your browsing experience with new per-site settings for Reader, page zoom, content blockers and more.

Enjoy refinements in Mail.

• Instantly find the messages most relevant to your search using Top Hits.
• Use Split View when composing new email in 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 favourite notes so they’re always at the top of the list.

Capture a moment in 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 Universal Clipboard.

• Copy and paste files between your Macs using standard copy and paste commands.

Safely store your family data in iCloud.

• 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 be 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.
• Experience greater responsiveness when performing common tasks like duplicating a file and finding the size of a folder.
• 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.

• Create and watch high-resolution video with High Efficiency Video Coding (HEVC), which uses up to 40 percent 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.

The update contains a couple of security fixes:

StorageKit
Available for: macOS High Sierra 10.13
Impact: A local attacker may gain access to an encrypted APFS volume
Description: If a hint was set in Disk Utility when creating an APFS encrypted volume, the password was stored as the hint. This was addressed by clearing hint storage if the hint was the password, and by improving the logic for storing hints.
CVE-2017-7149: Matheus Mariano of Leet Tech

Security
Available for: macOS High Sierra 10.13
Impact: A malicious application can extract keychain passwords
Description: A method existed for applications to bypass the keychain access prompt with a synthetic click. This was addressed by requiring the user password when prompting for keychain access.
CVE-2017-7150: Patrick Wardle of Synack

Homepage: https://itunes.apple.com/us/app/macos-high-sierra/id1246284741?mt=12