Winnowing is a process of separating substances based on the difference in weights of the constituent components. It is used when the impurities are much lighter than the desired substance such that the impurities can be carried away by the wind. The process is commonly used by farmers to separate lighter husk from heavier grains after the process of threshing. Winnowing is a simple and cheap method that doesnt require any machines for its function and is completely based on human activity. It is used to separate heavier and lighter components of a mixture by wind or by blowing air. The method of winnowing is used to separate useful components from the mixture in everyday life. The separation of substances can be done through various methods like hand-picking, threshing, sieving, winnowing, etc. . However, this process does not work for materials heavier than grains like stones.