The ratio of the stress in a body to the corresponding strain called elastic modulus, it is also called as coefficient of elasticity. It is the ratio of pressure applied to a body to the resistance produced by the body. If it is the ratio of longitudinal stress to stain than it is called young’s module . If it is the ratio of stress to the fraction decrease in the volume of the body then it is called bulk modules. If it is the ratio of tangential force per unit area to the angular deformation of the body then it is called module of rigidity or shear modulus.
For example, The brush handle has a higher elastic modulus than what the bristles of the brush tend to have because they are meant to bend easy when they are in our hair while we need the handle to be stiff.