Bio ethanol, or more commonly spelled as one word (bioethanol), is the same thing as ethanol, which is an alcohol created using biomass products, such as corn, sugar, and even cellulosic materials such as switchgrass or woodchips. This alcohol, or more specifically, ethyl alcohol, is often used as fuel. Some distinguish between bio ethanol and cellulosic ethanol, simply because the bio ethanol fuel is made from products that are fed to humans or animals. They are, however, largely the same — both are made using biological, or organic, sources.
The most common source for ethanol in the United States, as well as many other temperate countries, is corn. Corn has a fair amount of starch, which is what is needed during the fermentation process to make large amounts of bio ethanol. The corn is harvested and processed at an ethanol plant, and, depending on the procedure used, the dry grain may still have some nutritional benefit for livestock. In other cases, it will be useless.
Brazil, and a few other countries, use sugar cane, instead of corn, to make ethanol. The starch content in sugar is greater than in corn. As a result, more ethanol can be made more efficiently using sugar instead of corn. This is of great benefit to those countries where the climate is conducive to growing sugar cane, which is typically those areas between the tropics. Some sugarcane may be successfully grown as far as 30 degrees north or south of the equator, but the climate near those latitudes is typically less ideal.
There are many benefits of bio ethanol fuel. Not only can it be used as a fuel alone, but it can be used as a fuel supplement for gasoline-powered vehicles thereby stretching gasoline resources. It's also a beneficial fuel source for those countries that don't have any fossil fuel resources. Perhaps the most often touted benefit of bio ethanol is that it's typically a cleaner burning fuel than regular gasoline, though it still produces carbon dioxide.
While there are many benefits to bio ethanol, there are disadvantages as well. The energy used to produce the crops, and process the fuel, typically comes from non-renewable sources, making the net benefit somewhat questionable. Also, some argue that ethanol can take food away from both humans and animals, thus putting less on the food market, and inflating food costs overall. Finally, ethanol does not burn as efficiently as fossil fuels, giving vehicles that run on bio ethanol fuel a lower gas mileage.