The main function of an intrusion detection system (IDS) is to monitor network or system activities for signs of malicious behavior or policy violations. An IDS analyzes data traffic and generates alerts upon detecting anomalies or breaches, distinguishing between potential threats and normal activities. By providing real-time alerts, the IDS enables organizations to respond promptly to security incidents, enhancing overall network security. This is crucial for both preventive and responsive measures, ensuring that systems remain secure against evolving cyber threats.