wholegrain flour is milled with minimal processing, usually via stoneground milling (but not always – it will say on the packet if it is stoneground). The difference between wholegrain and wholemeal is that wholemeal is usually milled into white flour then has the meal/bran added back in. The reason for doing it this way is that it creates a smoother flour, which is appropriate for certain products.
We don’t do this for our retail products, however we do offer wholemeal to bakers as a bulk product.
Wholegrain contains more of the whole grain and has undergone less processing.