In a blog post introducing the 21H1 update, Microsoft's Head of Windows Servicing and Delivery John Cable said it will include a "scoped set of features improving security, remote access and quality". The changes appear to have been informed by user feedback, with Microsoft focusing "on the core experiences that customers have told us they're relying on right now".
In other words, Microsoft is using the update to improve the remote working tools that many of us are using on a daily basis. The most notable change is support for multiple cameras in Windows Hello. Many of us use our face to log into our PC these days, but if your laptop has a built-in webcam that supports face unlock, there's currently no easy way to set an external camera as the default. That's set to change in the 21H1 update, with the option becoming available in settings.
Microsoft's Defender antivirus software will also get some performance improvements, including faster document opening times. This should allow for more efficient real-time protection. The other important change will come on the management side, with Microsoft's Windows Management Instrumentation (WMI) Group Policy Service (GPSVC) updated to support remote working scenarios.
What's more, if you're coming from either version 2004 (May 2020) or 20H2 (October 2020), installing the update will be much quicker than usual. In the same blog post as above, Cable says it "will be delivered in an optimised way using servicing technology". This should put download times more in line with Microsoft's 'Patch Tuesday' monthly security updates.
These changes are unlikely to transform the experience for many people, but it offers more than is typical of a security-focused Windows 10 update, especially if you use an external webcam.
The 21H1 update is expected to arrive in June 2021, although members of the Windows Insider Program can download an early build right now. Just head to Settings > Update & Security > Windows Insider Programme and follow the instructions to get started. The Beta Channel is recommended to most users, striking a balance between getting updates early and not adversely affecting the functionality of your device.
As alluded to above, Windows 10 looks set for its biggest update yet in late 2021. Read more about the Sun Valley update here.