Difference between threshing and winnowing
Threshing is the process of loosening the edible part of the grain or seeds (or other crops) from the straw and chaff to which it is attached. It is the next process after harvesting in which stems and chaffs of wheat or paddy are separated from the grains. The process can be done manually by beating it on a solid surface or by using a threshing machine. Stalks or stems of crop plants and the chaff are soft materials whereas the grains themselves are very hard, therefore after striking it the heavy hard grains get detached from the soft stalks.
Winnowing is a farming method developed by ancient people for separating grain from the chaff. It is the next process after threshing which is very commonly used by farmers.The method involves throwing off the mixture into the air so that the wind blows away the lighter chaff, and the heavier grains fall back down.