Now in its third edition, this classic text remains the seminal resource for in-depth information about major concepts and principles of the cultural-historical theory developed by Lev Vygotsky, his students, and colleagues, as well as three generations of neo-Vygotskian scholars in Russia and the West. Featuring two new chapters on brain development and scaffolding in the zone of proximal development, as well as additional content on technology, dual language learners, and students with disabilities, this new edition provides the latest research evidence supporting the basics of the cultural-historical approach alongside Vygotskian-based practical implications. With concrete explanations and strategies on how to scaffold young children's learning and development, this book is essential reading for students of early childhood theory and development.