Bloom's taxonomy is a classification system used to define and distinguish different levels of human cognition. It was created in 1956 by Benjamin Bloom and his colleagues to promote higher thinking in education. The taxonomy categorizes learning objectives into three domains: cognitive, affective, and psychomotor. The cognitive domain involves thinking and reasoning skills and is divided into six categories. The affective domain relates to attitudes, values, and interests and has five categories. The psychomotor domain deals with manual and physical skills and is also divided into five categories. Bloom's taxonomy provides a framework to define learning objectives at different levels of complexity.