This chapter examines the definitions, purpose, and significance of group work in educational and professional contexts. Informed by social constructivist theory, it frames group work as a transformative approach that fosters learning through dialogue, interaction, and collaboration. Building on the insights of Vygotsky and Dewey, it emphasises that knowledge is best constructed in shared environments where individuals challenge, support, and learn from one another. Beyond classrooms, group work informs professional and therapeutic practice, providing frameworks for problem-solving, skill development, and support. The chapter distinguishes authentic collaboration from mere group activity and argues that group work cultivates cognitive growth, emotional resilience, and lifelong learning.