The update is for for Mac users running macOS Big Sur. The new software update includes bug fixes and enhancements to the operating system, and is therefore recommended for all Mac users running macOS 11 Big Sur.
Specifically, macOS Big Sur 11.2 is said to improve the reliability of Bluetooth connections, resolves an issue with external displays and some M1 Macs, fixes a problem where iCloud Drive could erroneously turn off, amongst other various improvements and bug fixes. The full release notes for macOS Big Sur 11.2 are further below.

‌macOS Big Sur‌ 11.2 improves Bluetooth reliability and fixes the following issues:

• External displays may show a black screen when connected to a Mac mini (M1, 2020) using an HDMI to DVI converter
• Edits to Apple ProRAW photos in the Photos app may not save
• iCloud Drive could turn off after disabling the ‌iCloud Drive‌ Desktop & Documents Folders option
• System Preferences may not unlock when entering your administrator password
• Globe key may not display the Emoji & Symbols pane when pressed

Some features may not be available for all regions, or on all Apple devices.
For more detailed information about this update, please visit: HT211896
 For detailed information about the security content of this update, please visit: HT201222
Big Sur users who have experienced slow performance, wi-fi problems, or more general problems with macOS Big Sur are all encouraged to download and install the macOS Big Sur 11.2 update.
Separately, iOS 14.4 and iPadOS 14.4 updates are available for iPhone and iPad, along with updates to tvOS and watchOS (see previous post).
See: Apple Site