Stress is the internal force that a material experiences when an external force is applied to it. It measures how much force is being exerted on the material relative to its size.
Strain, on the other hand, is the change in the material’s shape or size due to the applied stress. It shows how much the material stretches, compresses, or deforms compared to its original form.
In simple terms:
Stress is the force applied to a material.
Strain is how much the material deforms as a result of that force.