Constructivism is a theory of learning that suggests people actively construct their own understanding and knowledge of the world through experiences and reflecting on those experiences. The key principles of constructivism in education are that learning is an active process, knowledge is constructed rather than innate or passively absorbed, and learning is a social and collaborative process. In a constructivist classroom, the teacher acts as a facilitator rather than lecturer, and aims to engage students through hands-on activities, group work, and connecting new ideas to prior understanding in order to construct new knowledge.