I may only have a license to view the contents of a dvd, but at least I’ll always be able to view it as long as it’s in my possession and I have a dvd player.

Content you can only access remotely via someone else systems (or requiring remote authorization via there systems) can be taken away at anytime regardless of the terms of your license, even supposedly “indefinite/permanent/lifetime” licences.

Both of these items use the same term ‘purchase’. This term used to refer to the first situation only, but now it covers both.