Apple today released tvOS 18.1, the newest version of the tvOS 18 operating system that came out in September. tvOS 18.1 comes over a month after Apple released tvOS 18, and it is available for the Apple TV 4K and the Apple TV HD models.
tvOS 18.1 can be downloaded using the Settings app on the Apple TV. Open up Settings and go to System > Software Update to get the new software. Apple TV owners who have automatic software updates activated will be upgraded to tvOS 18.1 automatically.
tvOS updates are often minor in scale, and tvOS 18.1 doesn't seem to be an exception.
Apple still hasn't added the 21:9 aspect ratio for projectors or the new Snoopy screensavers that it promised at WWDC, but those features were not in tvOS 18.1 during the beta testing process, and we don't know what's new.
Apple shares release notes for tvOS in its tvOS support document, which is updated after each new version of tvOS comes out, so that should give us some insight into what's included in tvOS 18.1.