There are several common types of corn.
• Sweet corn - what we eat with a meal - high sugar content
• Field corn or dent corn - dried out and made into animal feed. Also used as a grain in making chips and corn tortillas - grow big, heavy ears - majority of commercially grown in the world
• Indian corn or flint corn - multicolored decorative corn. It's also dried and made into corn meal, polenta, etc.
• Popcorn - oldest domesticated type of corn. Range of colors. Harvested when ears are dry and kernels hard. Nebraska #1 producer in US.
• "Specialty" corns include many kinds such as heirloom varieties which are not mass-produced; and flour corn which has a soft texture making it easy to grind.