How intrusion detection system works?

An intrusion detection system (IDS) monitors network traffic and system activities for suspicious behavior or known threats. It analyzes data packets and logs against predefined rules and patterns, identifying potential security breaches or anomalies. When a potential intrusion is detected, the IDS generates alerts for administrators to investigate further. There are two main types of IDS: network-based (NIDS), which monitors network traffic, and host-based (HIDS), which focuses on individual devices.