About the macOS High Sierra 10.13.6 Update
This update is recommended for all macOS High Sierra users.
The macOS High Sierra 10.13.6 Update adds AirPlay 2 multiroom audio support for iTunes and improves the stability and security of your Mac. This update is recommended for all users.
AirPlay 2 for iTunes:
Control your home audio system and AirPlay 2-enabled speakers throughout your house.
Play music at the same time on multiple AirPlay 2-enabled speakers in your house, all in sync.
Other improvements and fixes:
Fixes an issue that may prevent Photos from recognizing AVCHD media from some cameras.
Fixes an issue that may prevent Mail users from moving a message from Gmail to another account.
