John Sweller is an Australian educational psychologist best known for developing the Cognitive Load Theory. This theory focuses on how the human brain processes information and the limitations of working memory. Sweller's research emphasizes the importance of instructional design in enhancing learning by reducing unnecessary cognitive load. Throughout his career, Sweller has contributed significantly to understanding how people learn and retain information. His work has influenced various fields, including education, psychology, and instructional design, helping educators create more effective teaching strategies that align with how the brain naturally processes information.