Somatotype is a classification system that categorizes human body types based on physical characteristics. Developed by William Sheldon in the 1940s, it identifies three primary body types: ectomorph, mesomorph, and endomorph. Ectomorphs are typically slim and lean, mesomorphs are muscular and well-proportioned, while endomorphs tend to have a rounder physique with more body fat. This system is often used in fields like fitness and nutrition to tailor exercise and diet plans according to an individual's body type. Understanding one's somatotype can help in setting realistic fitness goals and improving overall health and well-being.