where:
E is Young’s modulus
σ is the uniaxial StressStress is defined as a level of force applied on a sample with a well-defined cross section. (Stress = force/area). Samples having a circular or rectangular cross section can be compressed or stretched. Elastic materials like rubber can be stretched up to 5 to 10 times their original length.stress
ε is the strain along the direction of the applied stress

Relationship between the Elastic Moduli

E = 2G(1+μ) = 3K(1-2μ)

where:
E is Young’s modulus
Shear Modulus G*G or shear modulus is defined as the ratio of shear stress and shear strain.G is the shear modulus
K is the bulk modulus
μ is the Poisson number

The figure depicts a given uniaxial stress for tensile (extension, left) or pressure (compression, right). A material with low stiffness (red) provides a higher deformation than a material with high stiffness (blue). Young’s modulus is a measure of the stiffness.