Ethanol is alcohol derived from crops such as corn and sugar. It is used as a gasoline additive, which results in cleaner burning fuel with higher octane.

The most common blend of ethanol and gasoline in the US is E-10, 10% ethanol and 90 % gasoline. It can be used in regular engines.
Another blend is E-85, 85% ethanol and 15% gasoline, needs a (FFV) Flexible fuel vehicle.

FFV is a vehicle that can operate on any blend of ethanol up to 85%. If E85 is not available, the vehicle can operate on regular gasoline or any percentage of ethanol up to 85%.
You don't see Ethanol pumps in the South, but they are common in the Midwest.
Ethanol Fuel economy is lower, because it contains less energy content, therefore it has to cheaper than gasoline to be cost effective.

Ethanol used as a fuel is not a panacea, but is renewable, can lessen the dependency on foreign countries, burns cleaner and potentially is less expensive.