Enterprise and security updates comprise most of the update that launched today.
The update offers no new features; rather, it is focused mostly on enterprise and security updates. Consumer-facing changes include improved compatibility with some third-party USB devices and accessibility changes like improved VoiceOver navigation in Preview and Braille in the Mail app. The enterprise updates improve keychain performance and fix a few bugs.
As for the security updates, macOS 10.13.2 includes a permanent fix for the widely reported and previously addressed root user credentials bug, several issues related to the Intel graphics driver, the Mail app (S/MIME encryption issues), and more.
This is the second major update to macOS High Sierra after 10.13.1, which addressed the KRACK Wi-Fi vulnerability, added new emojis, and fixed several bugs.
Here are the full update notes Apple has provided to users in the App Store and its support documentation:
The macOS High Sierra 10.13.2 Update improves the security, stability, and compatibility of your Mac and is recommended for all users.