A Network Intrusion Detection System (NIDS) is a security tool designed to monitor network traffic for suspicious activities and potential threats. It analyzes data packets traveling across a network and identifies patterns that may indicate unauthorized access or attacks. By detecting these anomalies, NIDS helps organizations respond quickly to security incidents. NIDS operates by using various techniques, such as signature-based detection, which looks for known threats, and anomaly-based detection, which identifies unusual behavior. This system is crucial for maintaining the security of networks, protecting sensitive information, and ensuring compliance with regulations related to data protection.