What is SIEM (Security Information and Event Management)?
A SIEM aggregates security logs from every system in your environment, correlates them in real time, and alerts on suspicious patterns that no single log source could detect alone.
Modern SIEM products (Microsoft Sentinel, Splunk, Datadog Security, LimaCharlie) ingest logs from endpoints, identity providers, firewalls, cloud services, and applications. They apply detection rules, machine-learning baselines, and correlation logic to surface real incidents from the noise.
For most small Florida offices, full SIEM is overkill - Microsoft Defender + Microsoft 365 Audit Logs cover the basics. SIEM is most relevant for organizations with >100 endpoints, regulated data at scale, or active threat-hunting requirements.
Why it matters for Florida small business
If your security renewal questionnaire asks about 'centralized log monitoring,' your answer needs to demonstrate something - even M365 audit log review counts as a starting point.
What to do
Confirm M365 Audit Logs are enabled and someone reviews them at least weekly. For larger organizations, evaluate Microsoft Sentinel.