The elastic region refers to the part of a material's stress-strain curve where it can deform under stress but return to its original shape once the stress is removed. In this region, the material behaves elastically, meaning it can stretch or compress without permanent deformation. When a material is in the elastic region, the relationship between stress (force per unit area) and strain (deformation) is linear, following Hooke's Law. This law states that the amount of deformation is directly proportional to the applied stress, as long as the material remains within its elastic limits.