This book aims to address the topic of triage comprehensively, delving into its historical roots, purpose, current practices, and future trajectories. All professionals working in emergency settings have heard of triage. Despite its widespread familiarity, reliance on individual settings and systems remains predominant. This book provides readers with a foundational understanding of hospital triage in emergency departments and enhances their grasp of its functionalities. It develops risk stratification, provides a comparative analysis of triage systems, and evaluates their performance. Finally, this book addresses the needs for improvement in triage systems and presents possible short and long-term alternatives. It is a valuable resource for all healthcare professionals working in emergency department settings, nurses and physicians, as well as professionals who wish to enter the field of emergency medicine and urgent care.