An Intrusion Detection System (IDS) is a network security tool—either a device or software application—that monitors network traffic or system activities for signs of malicious activity, suspicious behavior, or violations of security policies. When such activity is detected, the IDS sends alerts to security administrators or a centralized security management system for further investigation and response.
The IDS continuously scans network traffic or system events for abnormal patterns or known attack signatures. It looks for specific patterns or signatures associated with known threats, such as certain malware or exploit code. It identifies deviations from normal behavior, which may indicate new or unknown threats. When suspicious activity is detected, the IDS generates alerts for security teams to review and respond to potential threats.