In Microsoft 365 Defender, security signals from across Microsoft 365 services are raised as alerts. Microsoft’s documentation defines an incident as “a collection of correlated alerts” that represent the end-to-end story of an attack. The incident object aggregates the related signals, entities, and evidence so analysts can triage and remediate holistically rather than handling individual alerts in isolation. Microsoft further explains that incidents “group together related alerts, assets, users, and evidence” to reduce noise and provide context for investigation, and that automated correlation “helps SOCs focus on what matters most” by stitching alerts from Defender for Endpoint, Defender for Office 365, Defender for Identity, and Microsoft Defender for Cloud Apps into one case. Within an incident, analysts see a timeline, impacted assets and users, alert details, and recommended actions, and they can trigger response measures (for example, isolate device, block URL/file, or disable user). This contrasts with events (raw telemetry), vulnerabilities (exposure findings managed by Defender Vulnerability Management), and Microsoft Secure Score improvement actions (posture recommendations). Therefore, in the Microsoft 365 Defender portal, an incident is specifically a collection of correlated alerts, designed to streamline investigation and coordinated remediation across the Microsoft 365 security stack.