Online Service Experience Packs in Windows 11 is a cloud service that improves the delivery experience of new changes and improvements to Windows 11. This is used to deliver Windows 11 updates quickly to the end user.
Along with the release of Windows 11 Build 25211, Microsoft releases Online Service Experience Pack - Windows.TestSettings.Account - version 2.1.169.0 to the insiders in the Dev Channel.
The Online Service Experience Packs work in a similar manner as the Windows Feature Experience Packs do. It enables the Microsoft Windows team to quickly make updates to specific areas outside of a major Windows update.
The difference between the two is that the Windows Feature Experience Packs can deliver broad improvements across multiple areas of Windows, whereas the Online Service Experience Packs are focused on delivering improvements for a specific area such as the new “Your Microsoft account settings” page.
The Online Service Experience Packs can be identified under Windows Update. For example, the new “Your Microsoft account settings” page would be displayed as “Online Service Experience Pack – Windows.Settings.Account” and a version number.
The latest Online Service Experience Pack version 2.1.169.0 displays it as "Windows.TestSettings.Account".