What is threshing? Where is it used?

Hint: As we know that most of the history of agricultural processing took a while and usually their wheat bushel took about an hour. Before the mechanization of threshing in the late eighteenth century, a quarter of the agricultural workforce was devoted to it. When the small grains grown in the early days of cultivation may be shelled with hand, yet the quantity increased, the grain may be threshed in the ground by using a stick.

Complete answer:
Threshing is the process of removing the edible part of the grain from the straw and this is the stage of preparation of the grain after harvest. In this process, it does not remove the bran from grain. It was designed to run a lot of water-powered flakes, but was not particularly successful. The first practical attempt to steer in the right direction was made in $1758$ by a Scottish farmer named Leki.
The original industrialization of threshing was invented in $1786$ and here, it fed loose sheaves, first to the ears and from a feed board between two floating revolving rollers to a beating cylinder. This threshing is mainly used in mustard seeds, to separate gram, wheat, rice, Sedimentation, Winnowing, Filtration and Sieving.

Note:
Threshing is a process which is used for the separation of grains from the straw. It is mainly used for Sedimentation, Winnowing, Filtration and Sieving. Insects from rice, hand picking, broken grains etc are the examples of threshing. And in the sedimentation process, there is a removal of solid particles from the solution or suspension.