Somatotypes are a classification system that categorizes human body types based on physical characteristics. Developed by William Sheldon in the 1940s, the system identifies three primary 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. Each somatotype represents a different combination of body composition and structure. While most individuals may exhibit traits from more than one type, the classification helps in understanding physical fitness, nutrition, and body image. This system is often used in fields like sports science and nutrition.