For us in the UK the definitions around cornmeal, corn flour, cornstarch can be a little confusing so here we begin to clarify this for you.
Cornmeal is a meal made from maize (corn). It is an international staple, used in cooking across the Americas, Africa, Asia, the Caribbean and Europe.
A meal is a coarse flour.
Cornmeal can be ground to differing consistencies i.e. coarse, medium and fine, but it is not ground as fine as a wheat flour such as plain flour (AP in the US).
So, here it is:
Corn = Maize
Cornmeal (US) = Polenta (UK, well Italy really, but this is the description we use in the UK)
Corn flour (US) = Maize flour (UK) very finely ground, used for making bread and tortillas.
Corn starch (US) = Corn flour (UK) this is the finely powdered starch extracted from the maize kernels, which is used as a thickening agent.
Boy, talk about two countries separated by the same language!!
The upside is that cornmeal is usually considered gluten free and there are hundreds of ways to use it, but a word of caution, it is often processed on the same machinery as grain containing gluten, so do check packaging for cross contamination notes before using it for anyone who has a gluten allergy.