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, such as unauthorized access or changes to files, by examining system logs and configurations. HIDS can alert administrators to potential threats, helping to protect sensitive data. Unlike network-based systems, HIDS focuses on individual hosts, making it effective for detecting internal attacks or malware. It can also provide detailed reports on system integrity and user activity, enhancing overall security by identifying vulnerabilities before they can be exploited.