Drm- Digital "rights" management, more like digital restrictions management is a thing that tries to make sure the things you own are restricted by someone else.
It s the reason some singleplayer games dont work offline, some apps wont let you record them or Blu Ray discs try to stop you from copying them. things that you own. Thwy are controlled by corporations that can say who can use the media. Even if a device is perfectly able to play a movie, Google can not allow it so Neflix would not trust the device.
Examples are Denuvo and Widevine
https://en.m.wikipedia.org/wiki/Digital_rights_management