A combine or more formally known as a combine harvester is an essential piece of equipment for grain harvesting. It was invented in the early eighteen hundreds and is one of the greatest time saving innovations invented to date in agriculture. A combine harvester has three main functions: reaping, threshing and winnowing. It is mainly used for grains such as oats, barley, wheat, corn, soybean and flax. The head of a combine is removable and customized for the harvesting of different types of crops. The leftovers are shot out back on the field after a combine harvests. This is usually dried and bailed for feed or livestock bedding.