Constructivism is a learning theory that posits that people actively construct their own understanding and knowledge through experiences and reflecting on those experiences. Key figures in constructivism include Piaget, who defined cognitive development stages; Bruner, who emphasized participatory learning; Vygotsky, who explored social learning and scaffolding; and Dewey, who believed learning should expand on experiences. Constructivism focuses on interactive, student-centered learning rather than traditional teacher-centered instruction. Under this theory, students construct knowledge through problem-solving, inquiry-based activities, and social learning experiences while teachers take on the role of facilitating understanding.