Constructivism is a learning theory that focuses on the learner constructing their own knowledge through active participation and hands-on experiences. Key aspects include students learning by doing, teachers using scaffolding to support learning, and students participating in the learning process. Jean Piaget and Lev Vygotsky contributed influential cognitive development theories related to constructivism, such as Piaget's stages of cognitive development and Vygotsky's zone of proximal development which emphasizes collaborative learning. Constructivism supports active, experiential, student-centered learning approaches that are well-suited for teaching subjects like math.