https://arstechnica.com/gadgets/2020/08/apples-ios-and-ipados-13-6-1-roll-out-to-all-users/

Apple has released software updates for three of its operating systems: iOS for iPhones and iPods, iPadOS for iPads, and macOS for Macs. The updates are small and focus on bug fixes rather than adding new features.

The updates are labeled iOS 13.6.1, iPadOS 13.6.1, and macOS 10.15.6 Supplemental Update. Typically, iOS or iPadOS updates that have two decimal points are bug-fix updates, and releases that bring new features have just one decimal point.