A corn thresher is a machine that is used to separate corn kernels from the cob. The machine consists of a rotating drum with serrated teeth or blades, which break the kernels away from the cob. The separated kernels are then discharged through an opening in the side of the drum, while the remaining cob is expelled through a separate outlet. Some corn threshers may also have additional features, such as a fan to remove debris and husks from the kernels.