An Intrusion Detection System (IDS) is a security system that monitors a network or a system for malicious or suspicious activities. It is designed to detect and alert administrators of any malicious activities or policy violations that occur on the network.
For example, an IDS can detect malicious activities such as port scans, buffer overflows, and denial of service attacks. It can also detect unauthorized access attempts, malicious software downloads, and data manipulation. An IDS can also be configured to detect specific types of malicious activities, such as SQL injection attacks or cross-site scripting attacks.