Intrusion Detection System 

An intrusion detection system (IDS) is a surveillance software or device designed to continuously monitor a network or systems for protection against hackers, malicious activity, or violation. This kind of suspicious activity is collected centrally using a system called a Security Information and Event Managementa (SIEM) or the violation can be reported to an administrator. To differentiate between a real hacking attempt and a false alarm, an intrusion detection system uses some alarm filtering techniques.