Thinking about it, I came across the terminology when I was deciding what licence to use for a side project I was coding, and it was on the webpages telling me about various licences folks use for open source projects.

So I’ve only learned this term from looking at licensing from the other side of the table, so to speak, so I suspect that most people who aren’t programmers wouldn’t come across it because it’s not even included in the text of most licences. It’s a unifying concept, rather than a contract term.

It’s always nice when I’m about to install some software and it says the name of a copyleft licence in aware of. When it says GPLv3 as the title, for example, I stop reading and say we’re good to go.