Corn here in UK
I am amazed by that information! I think that's a fairly recent development, following mass media.
Corn is maize in the US. Maize is maize in South Africa.
Wheat is wheat, you make bread from it.
You can make bread from other things like rye or spelt, which is a kind of wheat.
And there are other grains such as sorghum, barley and quinoa.
Those are my examples that spring to mind, mostly as a result of shopping around and researching my food.
LROBBINS is a scientist, I am an eater of grains.