This book offers an evidence-informed overview of how child welfare systems—primarily in the United States—operate, what outcomes they achieve, and how effectively they protect children from maltreatment, drawing on extensive scholarship and the authors’ decades of research and professional experience. While acknowledging structural inequities and complex family challenges that limit success, the authors conclude that child welfare services have meaningfully supported many of the most vulnerable children and families. The book aims to equip readers with a clear, practical understanding of child welfare’s purposes, practices, controversies, and future directions for improvement.