Send levels - what do they actually mean?

I know this is a dumb question, but I’ve been using Cubase for years and I’ve just started to wonder about the send levels slider…what does it actually mean?

It starts at -00 then goes up through 0 to 6.02 as far as I can see. But what is that scale measuring? I think of that slider as how much of the channel signal to send to the effect; in my head it 0-100%. But that’s clearly not what’s happening. So what is? Or if it is 0-100%, why isn’t labelled like that?

And I know it doesn’t really matter…it just matters how is sound, sure. But everything else in Cubase makes sense to me, but this seems…wrong.

Am I being an idiot?

It’s the same as a mixer fader - 0 is unity - 0 is 100% of the signal which will differ depending on whether or not you’ve got it pre/post fader. It’s measuring dbFS