Psychology is the scientific study of behavior and mental processes. It examines topics like perception, cognition, emotion, behavior, and social interactions. Psychology has roots in philosophy but became an independent science in the late 19th century. It uses scientific methods to observe, describe, predict, and explain human behavior and experiences. Psychology has various fields that study different topics like cognitive processes, abnormal psychology, development, and therapy. It also has many applications in areas like counseling, psychotherapy, education, health, and business.