> What’s the difference between this and “waterfall” then?
The difference between this and “traditional waterfall” is that you do this continuously, simultaneously with implementation, and not just once, up-front before building anything.
(At least that's the common picture of “waterfall” -- which of course proponents of various “agile” methodologies prefer to contrast their product against -- though IIRC Brooks or someone had proposed / recorded iteration on this in parallel with implementation long before the Agile Manifesto.)
The difference between this and “traditional waterfall” is that you do this continuously, simultaneously with implementation, and not just once, up-front before building anything.
(At least that's the common picture of “waterfall” -- which of course proponents of various “agile” methodologies prefer to contrast their product against -- though IIRC Brooks or someone had proposed / recorded iteration on this in parallel with implementation long before the Agile Manifesto.)