The combine harvester, or simply combine, also known as a thresher is a machine that combines the tasks of harvesting, threshing, and cleaning grain crops. The objective is to complete these three processes in one pass of the machine.
A forage harvesters, also known as a silage harvester, forager or chopper, is a machine which is used to produce silage. By chopping the crop into small chips . So it can fed to animals or stored for a longer period