Elasticity of demand

 
This concept of elasticity is very useful in a number of ways and yet it is a confusing term to a number of students. Elasticity means reaction or response of consumers to a certain variable.
 
Elasticity of demand is the responsiveness of quantity demanded to changes in any of the determinants of demand. How do consumers react to changes in the determinants of demand? When there is a change in any determinant, do consumers buy more, less or the same amount of the commodity.