What is the difference between cornmeal, corn flour and corn starch ?
Cornmeal is dried corn that is dumped whole into a mill and ground up. If you had a bunch of dry corn kernels you can toss them into a coffee grinder and make all you want.
Corn flour is similar, although it is generally ground, and milled and sifted until it gets to be flour instead of meal. It is much more of a fine powder.
Corn starch is more of an interesting thing. If you take a corn kernel it is made up of different parts... if you google 'diagram of a corn kernel' you will see that one of the components of the inside of the individual kernel is called 'endosperm'...
They have a method to removed the endosperm from the rest of the kernel...it is typically done by washing and cooking...that part of the inside of the kernel (the white part) dissolves easier.
Just like if you have ever boiled a pot a pot of spahetti noodles... the stuff that made the water milky is starch...if you don't rinse the noodles afer you are done they will stick all together into a big clump because of the stickiness of the wet starch that binds together.