As has now become a custom, Apple has released new OS updates for virtually all of its devices in one giant volley today. The releases include iOS 15.2 and iPadOS 15.2, macOS Monterey 12.1, watchOS 8.3, and tvOS 15.2
All of these are now publicly available on supported devices. All but tvOS are x.x feature updates, meaning that they actually add new features instead of just fixing issues.
Depending on the OS, those features may include SharePlay, Apple Music Voice Plan, the App Privacy Report panel, and more.