Corn or "Maize" is a domesticated strain of wild grass that does not grow in the wild. It must be tended to and cared for to survive. There is much debate over which grass it evolved from or who created the hybrid, but corn cobs have been found in archaeological excavations dating to 5000 BC.
Types of Corn
There are three types of corn. Flint corn, also known as blue or red corn, has a hard exterior and is used for popping corn and animal feed. The kind you find in the grocery stores is "Sweet" which can be eaten off the cob. Dent corn is also known as Field corn and is the best corn to make Masa Dough and Hominy with. It is also widely used in processed foods and also feed for cattle. Flour corn is usually white corn and it is used for making corn flour for baked goods.
Hominy or Pozole and Masa dough
First the Field corn is removed from the cob and dried. The dried corn is boiled in water with cal or slaked lime in it. Then the kernels are often left to soak in the water for 1 hour to 24 hours depending on what you are going to do with it. The cooked and soaked corn is called Nixtamal. The kernels are rinsed thoroughly and rubbed together to remove the skins. For hominy, the little brown tips called "hulls" are picked off which allows the corn to expand when cooked. Or you can grind or process the nixtamal into masa, a corn dough.
Corn that has been dried and ground to a coarse flour. If the hulls (skins) and germs (brown tips) are removed the meal will have a long shelf life. If the hulls and germs remain in the meal, it is more nutritious but wont last as long. It is used as a hot cereal or grits by adding boiling water to make a mush. It is also used to make cornbread.
Masa harina or dough flour is a flour made from dough. It is made by making nixtamal and removing the hulls from the corn. The kernels are ground into a dough and then the dough is dried. The dried dough is ground again into a very fine flour. To use masa harina, water or chicken broth, and sometimes lard and seasonings are added to form a dough. Masa Harina can be used for tamales or tortillas or to thicken sauces.
Corn flour is made by grinding up dried corn into a very fine flour. It is used in many of the same ways a wheat flour is used.