Failure theories are frameworks used to understand and predict the failure of materials and structures under various conditions. These theories help engineers and scientists analyze how and why materials break or deform, allowing for safer and more efficient designs. Common failure theories include the Maximum Stress Theory, Maximum Strain Theory, and Von Mises Criterion, each providing different criteria for assessing material failure. These theories are essential in fields like civil engineering, mechanical engineering, and materials science. By applying these concepts, professionals can improve the reliability of structures, such as bridges and buildings, and ensure that products, like machinery and vehicles, perform safely under stress.