Artificial Intelligence is entering a new era in which systems are no longer limited to generating predictions or assisting users with isolated tasks. Agentic AI represents this transformation by enabling intelligent systems to perceive their environments, reason over complex objectives, plan multi-step actions, utilize external tools, collaborate with humans and other agents, and continuously adapt to changing conditions. As autonomous capabilities mature, Agentic AI is rapidly becoming one of the defining research and application areas of contemporary artificial intelligence. This edited volume, Agentic AI in the Age of Autonomy with Concepts and Case Studies, has been prepared to provide a comprehensive perspective on this emerging paradigm. Rather than focusing solely on technical advances, the book brings together interdisciplinary contributions that examine the architectural foundations of agentic systems, human-agent collaboration, governance, domain-specific applications, and future research directions. The diversity of the chapters reflects our belief that the future of autonomous AI will be shaped not only by technological innovation but also by responsible design, societal acceptance, and practical deployment across different sectors. The book begins by establishing the technical foundations of Agentic AI, explaining the layered architectures, reasoning mechanisms, orchestration strategies, and collaborative models that enable autonomous intelligent systems. It then explores issues of trust, governance, ethical responsibility, and social acceptance, highlighting the importance of balancing autonomy with transparency, accountability, and human oversight. Building upon these conceptual foundations, the following chapters examine how autonomous AI agents are transforming software engineering from passive development tools into collaborative teammates, while also reviewing the growing role of AI agents in education through current architectures, opportunities, and pedagogical challenges. The educational perspective is further extended through the presentation of SymDevAI Edu, a supervised Agentic AI ecosystem that demonstrates how autonomous agents can support K-12 learning environments in real-world settings. The volume continues with practical case studies illustrating the adoption of Agentic AI across diverse application domains. These include intelligent destination management supported by tourism dashboards, the interpretation of radiological images through large language models as decision-support systems in healthcare, neuro-symbolic autonomous governance for financial execution, and the coordination of autonomous swarm drones for adaptive wildfire prediction and disaster response. Together, these chapters demonstrate that Agentic AI is evolving beyond a theoretical concept into a versatile technological paradigm capable of addressing complex real-world challenges. As editors, we hope that this book will serve as a valuable resource for researchers, graduate students, practitioners, policymakers, and technology leaders seeking to understand both the opportunities and the challenges presented by increasingly autonomous intelligent systems. By combining theoretical perspectives with practical implementations, this volume aims to encourage interdisciplinary collaboration and inspire future research on trustworthy, explainable, and human-centered Agentic AI. Finally, we would like to express our sincere gratitude to all chapter authors for sharing their expertise and contributing their valuable research to this volume. We also extend our appreciation to the Izmir Academy Association Publishing House for its continuous support in promoting open-access, interdisciplinary scientific publications through the Future Tech Horizons e-book series. We hope this book contributes to the ongoing global dialogue on the responsible development and deployment of autonomous intelligent systems.