SIEM is a technology that provides real-time reporting and long-term analysis of security events by combining the functions of security information management and security event management. It analyzes logs and events from different systems to speed up detection of and response to security threats, reduces duplicate event records through aggregation, and allows for forensic search of records and long-term event summaries. SIEM also provides details on the source of suspicious activity, such as user, device, and posture information, to help security engineers quickly assess security events.