Constructivism is a theory of learning that says learners actively construct knowledge based on their experiences. There are two main types: cognitive constructivism focuses on individual cognitive processes, while social constructivism emphasizes social interactions. Key components of constructivism include creating cognitive dissonance, applying knowledge with feedback, and reflecting on learning. Constructivist teaching approaches involve engaging students in meaningful problems, organizing curriculum around broad concepts, seeking student perspectives, and using assessment to guide learning. The goals of constructivist curriculum are to provide experience with the knowledge construction process, multiple perspectives, and embedding learning in realistic contexts through authentic tasks.