Digital Rights Management is something that is coming to your computer and your phone and all your other devices.
It is intended to protect the creator of an "electronic software based something" from use from folks who haven't paid for that privilege.
Issue is that it doesn't work well or smoothly and that it requires constant fiddling to keep it working at all.
DRM will get in the way of you viewing a free movie from Amazon, since Amazon apparently doesn't really get that they have to keep their DRM tuned for a whole variety of use methods.
Amazon instituted DRM and unleashed a big furball of issues with their service.
In response to the furball Amazon has dropped back to only supporting vanilla I-OS and vanilla MS (current versions only) and of course their Kindle Fire products. This is a choice Amazon is now making and they will pay for their lazy choice by having irate customers leaving their service.
Microsoft will certainly use DRM to keep you from using their products except strictly according to the limited license. They have never had this ability before and just about all of us have stretched the MS's license in some fashion over the years. People expect this from MS, but now may find themselves held strictly to the letter of the agreement.
They don't expect it from the little incidental guys, but it is coming.
Example, Novell is going on the selling block soon as they are about bankrupt. A patent troll buys the corpse of Novell and then starts tracking all the folks using the various drivers and bits and pieces to collect evidence of existing use. Then they push a DRM'd update out and let it settle into place, then trigger it at a license cost of $1,000 per customer per year.
Novell is EVERYWHERE in business and although Novell was very open over the years and permitted such things to expand through the ecosystem the new troll owner may not be so friendly.
This is a simple example that hopefully will never happen.
But I have seen Amazon totally screw themselves up just trying to use DRM to protect streaming of some videos that they are giving away for free. DRM will be cursed by you sometimes in the next year as you stumble across it not working out as intended by the folks trying to use it.
Good luck, you may need it.