This volume demonstrates that migration- and diversity-related concepts are always contested, and provides a reflexive critical awareness and better comprehension of the complex questions driving migration studies. The main purpose of this volume is to enhance conceptual thinking on migration studies. Examining interaction between concepts in the public domain, the academic disciplines, and the policy field, this book helps to avoid simplification or even trivialization of complex issues. Recent political events question established ways of looking at issues of migration and diversity and require a clarification or reinvention of political concepts to match the changing world. Applying five basic dimensions, each expert chapter contribution reflects on the role concepts play and demonstrates that concepts are ideology dependent, policy/politics dependent, context dependent, discipline dependent, and language dependent, and are influenced by how research is done, how policies are formulated, and how political debates extend and distort them. This book will be essential reading for students, scholars, and practitioners in migration studies/politics, migrant integration, citizenship studies, racism studies, and more broadly of key interest to sociology, political science, and political theory.