Both open-pollinated and hybrid corn are widely grown by farmers and hobby gardeners, and both have their place. Hybrid varieties are created deliberately or accidentally by having corn of one variety pollinate corn of another variety. The resulting crossbreed will have some characteristics of each parent, but to get next year's seed you will need to cross the original two parents again. Open-pollinated plants, or those whose seeds are pollinated naturally, are said to "breed true," meaning their seed will reproduce the characteristics of the parent plant.
Open-pollinated corn varieties are the original cultivars, whose seeds have been saved and replanted for thousands of years. Improvements in the cultivars are brought about by selecting those plants that show desirable characteristics, and saving their seed to plant the next year's crop. They are available in a wide range of colors and sizes. Open-pollinated corn is quite hardy, usually requiring less water, less fertilizer and generally less care than hybrid varieties.
Hybrid corn is produced by cross-breeding two parent strains, carefully selected for desirable characteristics. This is a two-year process, with the first year's growth providing the second year's seeds. Hybrids are usually produced by farmers under contract to seed companies, rather than by individual farms and farmers. Hybrids are manipulated to produce extra-sweet corn for eating fresh, or for less-obvious characteristics such as resistance to a given disease or pest, or an ability to survive specific herbicides.
Which corn to grow is up to each individual gardener. Homesteaders may choose open-pollinated corn from frugality or a desire to avoid supporting the giant seed companies. Hobbyists might choose to grow a rare open-pollinated variety to help preserve it for future generations. On the other hand, a small farmer growing for the local farmers market is likely to favor a super-sweet hybrid, because these are the most popular for fresh eating. Other factors such as local climate and growing season are also important considerations.