Security term · last reviewed 2026-07-07
SIEM
Also known as: Security Information and Event Management
A SIEM collects, normalizes, and correlates logs and events across an environment to detect and alert on security activity; it presumes a team to run it, so it is usually premature for early startups.
How it works
A SIEM (Security Information and Event Management) system collects logs and events from across your environment (servers, applications, identity providers, network devices), normalizes them, and correlates them to detect and alert on security-relevant activity. It is the central nervous system of a security operations program: everything sends its logs to the SIEM, which runs detection rules, raises alerts, and keeps the searchable history an analyst or auditor needs. Examples include Splunk, Microsoft Sentinel, and Elastic Security. Modern SIEMs increasingly overlap with SOAR for automated response.
When it matters
A SIEM matters once you have a security team (or a managed provider) to actually watch and tune it, and once compliance or scale demands centralized detection. For an early-stage startup it is usually premature: retained audit logs from your identity provider and cloud platform answer the "who did what, when" questions you will actually get asked, without a SIEM to run. See The Solo Founder's Identity and Security Stack and Pass SOC 2 as a Seed-Stage Startup.
Common misconceptions
- "A SIEM secures you by itself." It detects and alerts; without people to respond, alerts fire into a void.
- "Every startup needs a SIEM." Most small teams do not; retained audit logs are enough early.
- "SIEM and [SOAR](/glossary/soar/) are the same." SIEM detects; SOAR orchestrates and automates the response.
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