A Network-Based Intrusion Detection System (NIDS) is a security solution designed to monitor network traffic for suspicious activities. It analyzes data packets traveling across the network to identify potential threats, such as unauthorized access or malicious behavior. By examining patterns and signatures, NIDS can detect intrusions in real-time and alert administrators to take action. NIDS operates by placing sensors at strategic points within the network, allowing it to capture and analyze traffic without affecting performance. This system is essential for organizations to protect their digital assets and maintain the integrity of their network infrastructure.