A Host-Based Intrusion Detection System (HIDS) is a security tool that monitors and analyzes the activities on a specific computer or server. It checks for suspicious behavior, unauthorized access, and changes to system files, helping to identify potential security breaches. HIDS operates by collecting data from the host system, such as logs and file integrity, to detect anomalies. HIDS can alert administrators about potential threats in real-time, allowing for quick responses to incidents. Unlike Network-Based Intrusion Detection Systems (NIDS), which monitor network traffic, HIDS focuses on the individual host, providing a more detailed view of security events and vulnerabilities.