Asecurity information and event management system (SIEM)is designed to centralize and analyze security-relevant data to supportthreat detection, compliance reporting, and incident management. SIEM platforms ingest logs and telemetry from many sources such as servers, endpoints, network devices, firewalls, intrusion detection systems, identity providers, cloud services, and business applications. They normalize and correlate these events so analysts can identify suspicious patterns that would be difficult to see in isolated logs, such as repeated failed logins followed by a successful login from an unusual location, privilege escalation, lateral movement indicators, or abnormal data access.
Cybersecurity operational guidance emphasizes SIEM value in three main areas. First,detection and alerting: correlation rules, behavioral analytics, and threat intelligence enrichment help surface high-risk activity. Second,incident response support: SIEM provides timelines, evidence preservation, triage context, and query capabilities that help responders scope and contain incidents. Third,compliance and audit readiness: centralized log retention, integrity controls, and reporting demonstrate that monitoring and control requirements are operating.
The other options do not match the definition. SaaS is a delivery model, not a specific security monitoring capability. A threat risk assessment is a process, not a software product for event collection and correlation. A CASB focuses on governing and protecting cloud application usage, whereas SIEM focuses on cross-environment event aggregation, correlation, and security operations monitoring.
