Constructivism is a theory that learning is an active process where learners construct knowledge from their own experiences and interpret information through personal and cultural lenses. Jean Piaget's model of cognitive development outlined four stages - sensorimotor, preoperational, concrete operational, and formal operational - where children progress in their ability to understand abstract concepts. Jerome Bruner's discovery learning theory proposed that learning occurs through problem-solving and relating new information to prior knowledge. Lev Vygotsky's social development theory emphasized that social interaction and guidance from more knowledgeable others aids learning, and defined the zone of proximal development as what one can learn with assistance versus independently. Constructivist classrooms allow students to learn through hands-on activities appropriate to their