Is there a difference between "Grand Strategy" and 4X?

Thinking about this last night trying to describe the difference to a friend and I really couldn’t come up with much other than if it’s made by Paradox it’s probably “Grand Strategy”.
Is there a definition out there that makes the differences clear, or are there even any differences?

I think the whole resource exploitation aspect is de-emphasized in Paradox-style grand strategy. In EU4, for example, they’re mostly interchangeable, whether they be gold or grain or slaves. In CKII they’re missing altogether.

Same with “eXplore.” There’s no exploration to be done, because you can see the whole map all the time. Grand strategy games pull you all the way back so that you can see everything. They’re computerized board games, which makes sense, because the term “grand strategy” is a board game term.

4X is a story that starts from the beginning with fog of war to every direction. Grand Strategy games start in medias res.

Matrix Games has done the “World in Flames” [monster] board game for the PC. You refight WW2, any or all theaters. I consider that to be “grand strategy”.

Sure, Germany can “expand” (conquer Poland, France, etc.), and “exploit” (using conquered resources and factories for production), there is no “explore” at all. Nations can not develop more than a couple new (synthetic oil) resources that didn’t exist at game start, either, nor colonize (building new populations, cities).

I think you’d struggle to find a 4X game that wasn’t Grand Strategy, but there are Grand Strategy games that aren’t 4X.