This chapter provides an inclusive overview of Intrusion Detection System (IDS) and its pivotal role in modern cybersecurity frameworks. The authors explore the foundational concepts and operational mechanisms of IDS, emphasizing their importance as a critical layer of defense against cyber threats. The study investigates various types of IDS, including signature-based and anomaly-detection systems, to highlight their respective methodologies and effectiveness in network security. They examine the prevalent threats and vulnerabilities that challenge IDS, alongside effective strategies for incident handling and system resilience. The chapter also discusses advanced evasion techniques employed by attackers to bypass IDS defenses and presents a taxonomy of IDS, incorporating deep learning, machine learning, and optimization algorithms. Additionally, the authors analyze datasets pertinent to IDS research and their role in enhancing system performance. With this analysis, they aim to clarify the constantly changing field of IDS and their crucial function in protecting digital networks.