The update was released with build numbers for iOS 12.5.4 and iPadOS 12.5.4. The system is designed for iPhone 5s, iPhone 6, iPhone 6 Plus, iPad Air, iPad mini 2, iPad mini 3, and 6th generation iPod touch. That is, we are talking about devices that do not support the current version of iOS 14.
The new software contains important security updates, according to Apple. The firmware has eliminated the vulnerabilities of the system, as well as the WebKit engine.
Apple strongly recommends installing new software. By the way, it is already available for download.