Television is scheduled broadcast media, sent through UHF signal, satellite or cable, subsidised by advertising or public funding. The key word is scheduled. You watch at the whim of the broadcaster, not at your convenience.
Everything else is video, whether it's your own PVR recording of a scheduled broadcast, a purchased DVD, Blu-ray, VHS, or download, or whether it's streaming on demand.
The device that you watch it on is irrelevant.
In current society, the former is diminishing in popularity while the latter is increasing.
The lines blur though, as without scheduled broadcasts, you can't have time-shifted PVR, and there will be a lot less content to download or stream. And as long as there are live events, there will always be room for scheduled broadcasts. But I contend that television as I knew it growing up, really doesn't exist anymore.