The following article provides a summary of the theory of learning known as constructivism. Constructivism has received a great deal of recent attention in the educational literature, and as a result, has been defined in multiple ways. So many different definitions currently exist some scholars believe constructivism has been emptied of meaning altogether. The following will attempt to bring some clarity back to the theory by focusing on two different strands of constructivism; cognitive constructivism, as outlined in the work of Jean Piaget, and social constructivism, as outlined in the work of Lev Vygotsky. Implications for teaching are introduced, as well as an example of a constructivist classroom activity. The summary also introduces the larger epistemological debate surrounding constructivism.