macOS Sierra 10.12.6 for Mac, iMac si MacBook it was launched a short time ago. As with iOS 10.3.3, the new version of Sierra does not bring visible changes, but only solves security and stability issues, about which Apple does not offer many details. In this sense, politics Apple is very clear. Not Reveals vulnerabilities Discovered in their own systems, so that they can not be exploited by malicious people.
What we know concretely about this update is that it comes "bundled" with an update for iTunes. Application of synchronization, media and management a Apple reached 12.6.2 version, and the iTunes update is available on both macOS and the Windows.
Download & Install macOS Sierra 10.12.6
Normally, within 24-48 hours of the release of the update, all users are notified via Notification Center about the possibility of download and installation. If this notification doesn't appear, go to App Store > Updates.
Apple is preparing to launch the next major operating system for this fall Mac, macOS High Sierra.