This is a distinction that does not matter to most non-technical people.
Well I mean unless you're inspecting it with a hex editor, you're not looking at the csv file itself. Even then, I suppose you could say that's not even the file itself. An electron microscope perhaps? But then you've got the whole Heisenberg issue, so there's that.
That's not true either, try it yourself with a simple csv file, open it, add a row and save - you'll see the original update