What is the difference between IDS and IPS?

An Intrusion Detection System, or IDS, monitors network traffic or system activity for suspicious patterns and generates alerts but does not block traffic. An Intrusion Prevention System, or IPS, sits inline in the traffic flow and can automatically block or drop malicious traffic in addition to alerting. Both use signature-based detection that matches known attack patterns and anomaly-based detection that identifies deviations from normal behavior. ---