What is SIEM (Security Information and Event Management)?
SIEM is a security platform that aggregates logs and events across an organization, correlates them to detect threats, and supports investigation, alerting, and compliance reporting.
SIEM (Security Information and Event Management) is the security team’s central nervous system: a platform that aggregates security-relevant logs and events from across an organization — endpoints, servers, cloud accounts, identity providers, firewalls, applications — correlates them to detect threats, and provides the search, alerting, and reporting that investigations and compliance require.
What a SIEM does
- Collection & normalization — ingest logs from hundreds of sources and map them onto a common event schema
- Correlation & detection — rules and analytics that turn raw events into alerts: impossible-travel logins, privilege escalation chains, data exfiltration patterns
- Investigation — fast search across months of history to reconstruct what an attacker did
- Case management & response — triage, assignment, and (with SOAR integration) automated playbooks
- Compliance — retention and reporting for PCI DSS, HIPAA, SOC 2, ISO 27001
SIEM’s economics problem
Security telemetry is the highest-volume, longest-retention data in the company — cloud audit trails and authentication logs alone can dwarf application logs, and compliance regimes demand months-to-years of retention. Traditional per-GB-per-day SIEM pricing forces the worst possible trade-off: filtering out the data you might need for the investigation you haven’t had yet. This is why modern security architectures separate the storage layer (cheap, complete, object-storage-based) from the detection layer.
SIEM and observability convergence
The raw material of SIEM is the same as observability: logs, events, aggregation pipelines. Teams increasingly route security telemetry — Okta events, Falco runtime alerts, VPC flow logs, WAF and CloudTrail logs — into their observability platform, gaining one query surface and one retention policy for both operational and security data.
Security analytics with OpenObserve
OpenObserve serves as a high-volume, low-cost security log backend: object-storage retention makes keeping everything affordable, pipelines handle normalization and PII redaction in flight, and SQL-based alerting powers detection rules across sources — the SIEM data layer without SIEM data pricing.
Frequently asked questions
What is the difference between SIEM and log management?
Log management is the general-purpose foundation - collecting, storing, and searching logs. A SIEM is a security-specialized layer on top - detection rules, threat correlation, case management, and compliance reporting. Modern platforms blur the line, since the hardest SIEM problem (affordable retention of high-volume security logs) is a log management problem.
Why are SIEM costs so high?
Traditional SIEMs price by ingested volume per day, and security telemetry - authentication events, cloud audit trails, endpoint and network logs - is enormous. Teams end up filtering out data they may later need for investigations. Storing security logs on object storage changes the economics of long retention.
What is the difference between SIEM and SOAR?
SIEM detects and alerts; SOAR (Security Orchestration, Automation and Response) acts on those alerts with automated playbooks - enriching indicators, opening tickets, isolating hosts. SOAR consumes what a SIEM produces, and many suites now bundle both.
Related terms
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