[tpoacher]

Indeed.

The best way to make the distinction really obvious is the phrase: "Github is to git what Pornhub is to porn".

Alas, not a phrase you can use in an educational setting though. And I haven't really found other "hub" examples which would be as instantly recognisable and demonstrative of the difference.

[pwdisswordfishy]

It's a good metaphor, and one could easily substitute "YouTube" into the explanation in really sensitive situations. In less sensitive situations, you might be able to still use "PornHub" so long as you do enough throat-clearing to make it seem like you're not speaking glowingly of it, and YouTube is helpful here, too.

PornHub didn't invent online videos, and the fact that just because someone was talking about watching a video online doesn't mean it wouldn't be really weird for someone else to assume that they meant it was something on PornHub, instead of just an ordinary video on YouTube.