An engineering stress-strain curve illustrates the mechanical response of a material subjected to uniaxial tensile loading. Initially, the material undergoes linear elastic deformation governed by Hooke's law (σ = E · ε), where strain is fully recoverable. Beyond the yield strength (σ_y), plastic deformation begins as dislocations proliferate, leading to work hardening until reaching ultimate tensile strength (UTS), after which localized necking leads to ductile fracture.