There are two major types of corn: Sweet Corn and Field Corn. Their growing habits and usage are quite different.
Field corn grows much taller and has fuller leaves than the Sweet corn. The Sweet corn looks short and flimsy.
Field corn is left in field to die before harvesting, because drying on the plant is important part of the field corn growing cycle. Can start in October and thru December.
Sweet Corn is harvested much earlier, in "Kernel Milk" stage, which is approximately one month after a "silk tail" emerges from the cob. This happens in the middle of Summer.
Field corn is usually non-sugary type, kernels are hard and tasteless.
Sweet corn contains lots of sugar, kernels are sweet and juicy - perfect for fresh eating or snack.
Sweet Corn is mostly sold fresh on the cob, eaten fresh or slightly cooked, can also me canned or frozen.
Field Corn is processed into corn meal or corn flour and used as ingredient for many foods that contain corn.
How to grow corn
Soak seeds overnight in warm water before planting. Choose full sun area in the garden for planting. Plant directly in the field 2 weeks before the last spring frost in your area. Plant seeds 2.5" deep into the ground and 2' apart from each other. Water regularly.