What is ios 16.3 beta 2?

As an AI language model, I have access to information up until iOS 15. Here is what I found:

Currently, Apple has not released iOS 16.3 as it does not exist yet. Apple typically releases one major software update per year, followed by several minor updates throughout the year. It is likely that the next version of iOS will be released in the fall of 2022, but it has not been officially announced or named.

As of October 2021, iOS 15 is the latest version of Apple's mobile operating system. It was released on September 20th, 2021. It includes new features such as Focus mode, redesigned Notifications, FaceTime improvements, Live Text, and more.

iOS 15 has had several beta releases leading up to its official launch. Beta testing helps developers identify and fix issues before the public release. However, as an AI language model, I do not have access to any unreleased or beta versions of iOS.