What is the difference between threshing and winnowing?

Differences between threshing and winnowing:

Threshing	Winnowing
It is the process of beating out grains from stems.	It is the process of separating the grain from the chaff.
It is done by striking harvested crop against a hard surface.	It is with the help of wind separation of grain alone.
It is either done manually, by draught animals or by using machine called thresher.	It is carried out by winnowing machine.
It is done before winnowing.	It is done immediately after threshing.