This book offers a comprehensive and accessible introduction to the world of intrusion detection. Designed for beginners and those seeking a foundational understanding, it covers the core concepts, techniques, and tools used to identify and respond to malicious activity within computer systems and networks. This book has been used in multiple college-level courses with a focus on hands-on learning. This book is ideal for: · Students studying cybersecurity · IT professionals new to security · Anyone interested in learning about intrusion detection · Security enthusiasts The book provides a strong foundation for anyone interested in a career in cybersecurity or looking to enhance their knowledge of intrusion detection techniques. The updated version provides additional insights on emerging Artificial Intelligence (AI) threats, the growing concern of online criminal cartels, and how to leverage AI tools to increase your cybersecurity awareness and productivity.