'As Dug' should be the cheapest available material from a quarry. With me, that means occasional chunks of up to 400mm and then everything right down to dust as well. You can also ask for 'crusher run' which has the biggest chunks taken out, and would be my choice for making a road. You may be offered 'type 1' (aka sub base) which is similar but a bit better screened and is what you would use for a good surface that can be rolled smooth (and if necessary overlain with tarmac)- of course the more refined something is, the more you pay.
'Gravel' means larger stones only, i.e. the dust and grit is removed. Makes it free draining and also looks nicer, but doesn't pack together as well- lay it too deep and you create a gravel trap. More expensive than the stone that still has the dust etc in it.
Nb the above relates to where materials are quarried from solid stone, you may have other options locally depending on your geology.