Apple has shipped updates for iOS 16.7.4 and iPadOS 16.7.4, updates that can be installed on iPhones and iPads not running the latest operating system versions.
Arriving at the same time as the iOS 17.2.1 incremental update, Apple has introduced similar versions for iOS 16.7.4 and iPadOS 16.7.4.
The updates apply to the previous generation of the operating systems, but rather than including feature changes, the incremental updates tend to consist of bug fixes and performance improvements.
Apple doesn't usually offer details of these iOS and iPadOS incremental updates unless they are significant enough to explain, such as some security elements. These typically appear on its Apple Security Releases page.
The build number for iOS 16.7.4 and iPadOS 16.7.4 is 20H240.
Users can apply the updates in the usual manner if not performed automatically. Manual updates are handled in the Settings app, by selecting General then Software Update, then the update itself, and finally following the on-screen instructions.