An audit log is a record of relevant actions and events that helps organizations review activity, support investigations, and demonstrate accountability.
An audit log is a record of relevant system or user activity kept for review, accountability, and investigation. In plain language, it is the evidence trail that helps an organization understand what happened, when it happened, and who or what performed the action.
Audit logs matter because security decisions and investigations need evidence. Without reliable records, organizations struggle to reconstruct incidents, verify privileged actions, or show that controls are being followed.
They also matter because accountability is a control in itself. When important actions are recorded and reviewable, abuse and error become easier to detect and harder to hide.
Audit logs appear in cloud platforms, identity systems, administrative consoles, databases, and regulated business processes. Teams use them in Security Information and Event Management, internal investigations, post-incident analysis, and governance reviews.
Security teams connect audit logs to Log Correlation, Indicators of Compromise, Segregation of Duties, and Compliance Framework.
| Characteristic | Why it matters |
|---|---|
| Action detail | Shows what changed or what was attempted |
| Actor identity | Shows who or what performed the action |
| Time accuracy | Helps reconstruct sequence during investigation |
| Integrity protection | Makes the evidence more trustworthy |
| Retention | Keeps records available long enough for review and response |
A cloud administrator changes access policy on a production resource. The audit log records who made the change, when it occurred, and what action was taken. If the change later contributes to an incident, investigators have a reliable starting point.
An audit log is not the same as every raw operational log. Audit logs are especially valuable because they capture accountable actions and events that matter for review, governance, and investigation.
It is also not useful if it exists only in name. Logs need appropriate integrity, retention, and access control to remain trustworthy.