An intrusion detection system (IDS) serves to monitor networks for malicious activity or policy violations. It analyzes traffic patterns and system behaviors to identify potential threats, triggering alerts when suspicious activities are detected. IDS can be categorized into host-based (monitoring specific devices) and network-based (monitoring entire networks). By providing real-time alerts, IDS helps organizations to respond promptly to security breaches and mitigate risks. Integrating IDS with other security measures enhances overall cybersecurity posture, ensuring that sensitive data remains protected against unauthorized access and potential attacks.