Structural modification is the deliberate alteration of the physical, chemical, or structural arrangement of a system, material, or entity. As an academic concept and methodological approach, it investigates the relationship between intrinsic structure and extrinsic properties or performance, exploring how targeted changes at various scales (e.g., atomic, molecular, macroscopic) impact behavior and function. Its key characteristic is the intentional engineering of structure to achieve specific, desired outcomes; its significance lies in its fundamental role across diverse scientific and engineering disciplines for designing tailored materials, optimizing systems, and enabling novel technologies.