https://www.pcgamer.com/windows-10-update-for-october-brings-directx-raytracing-to-everyone/

The Windows 10 update for October is live, bringing with it new features like Your Phone, which simplifies interactions with Android devices, changes to the To-Do app, updates to Outlook.com, and more. Of particular interest to us is DirectX Raytracing (or ray tracing, if you prefer), which is now fully supported, meaning that you no longer have to enable developer mode to see what it can do. 

"Real-time raytracing is often quoted as being the holy grail of graphics and it’s a key part of a decades-long dream to achieve realism in games," Microsoft said in a Developer Blog update, apparently without concern about overselling the feature.