Apple releases OS 16.4 for iOS, iPadOS, tvOS, plus watchOS, HomePods and Ventura
Apple on Monday, March 28 let a lot of cats out of the bag with important 16.4 updates across the Apple device spectrum, and then followed later in the day with OS 15.7.4 updates for older Apple devices, and updates for Big Sur and Monterey on the Mac.
Always make sure you have a recent backup of each of your devices before applying the latest updates.
You can see the full list of Updates on this Apple site page.