Compliance (mechanical engineering) is the measure of the deformation of a material, structure, or component in response to an applied force or stress. It quantifies the degree to which an object yields or changes shape under load, and is defined as the ratio of displacement to applied force (or strain to applied stress, depending on context). This concept represents the inverse of stiffness and is fundamental in the analysis, design, and characterization of mechanical systems, materials, and structures, influencing factors such as flexibility, load distribution, vibration characteristics, and the interaction between components in various engineering applications.