I think it’s both. You activate and deactivate it in the mods menu.

I didn’t realise the new stuff was mods and I’ve just been playing regular factorio for the last week. I should have been in space two science packs ago!

I have a colleague who is trying hard to do it, but it isn’t good enough yet fortunately. I point out as many issues as I can to deter him but it ain’t working.