Microsoft Edge is a new web browser added in Windows 10, and will be available across the Windows 10 device family. It is fast, compatible, and built for the modern Web.
Some websites that stream music or videos use Digital Rights Management (DRM) to help protect against copying the streamed content. This may require saving data locally on your device.
Since you can download or otherwise obtain this type of media while using Microsoft Edge, the Let sites save protected media licenses on my device setting allows sites that offer this type of protected media to save DRM data on your device, including a unique identifier (ID) and media licenses (which make sure you have permission to access the media). This information is then retrieved by the websites you visit that host the protected content in order to allow you to use that content.
Turning off this setting prevents new media licenses from being saved on your device. Turning it back on will reset your unique ID and allow you to download and otherwise obtain protected media through Microsoft Edge.
This tutorial will show you how to turn on or off to Let sites save protected media licenses on my device in Microsoft Edge for your account in Windows 10.