Today is first Patch Tuesday of 2021 and Microsoft is rolling out a new cumulative update for all supported version of Windows. The cumulative update comes with security fixes for the system, browsers, core components and other basic functions. Devices using Windows Update for Business or that connect directly to Windows Update are not impacted. Device owners will only be impacted if they have already installed any Latest cumulative update (LCU) released September 16, 2020 or later and then proceed to update to a later version of. Windows 10, version 1809 or later, version 20H2 is KB 4598242.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-cumulative-updates-kb4598229-and-kb4598242-released/