What Defender for Endpoint does
Defender for Endpoint is the EDR component of Microsoft 365's security stack. It continuously monitors endpoints for behavioural anomalies, runs machine-learning detection on file and process activity, applies attack surface reduction rules, exposes a vulnerability management dashboard tied to your endpoint inventory, and feeds signals into Defender XDR and Sentinel for cross-domain correlation.
P1 vs P2 — what changes
Defender for Endpoint P1 (included in M365 E3) covers EPP (next-generation antivirus), attack surface reduction, web content filtering and basic EDR. P2 (in M365 E5) adds full EDR with automated investigation, threat & vulnerability management, advanced hunting in the security graph, Microsoft Threat Experts (MDR-style guided hunting), and the high-end attack simulator.
When Defender for Endpoint replaces third-party
Defender for Endpoint P2 is competitive with CrowdStrike Falcon, SentinelOne and Carbon Black — and often cheaper for organisations already in M365 E5. The integration with Entra Conditional Access (block sign-in from non-compliant devices) is genuinely unique. Australian organisations consolidating tools typically retire Sophos, Trend Micro or McAfee on the strength of Defender alone; replacing CrowdStrike or SentinelOne is more nuanced and depends on threat-hunting workflow preferences.