Both antivirus (AV) and Endpoint Detection & Response (EDR) live on your endpoints, but they operate at different levels. AV reacts to known bad; EDR watches for bad behaviour. Here is the practical difference.
Antivirus (AV)
- ✅ Signature-based scanning of files
- ✅ Cheap, comes bundled with the OS
- ✅ Catches commodity malware fast
- ❌ Misses fileless / living-off-the-land attacks
- ❌ No visibility into lateral movement
- ❌ Reactive — triggers only when a known payload hits disk
EDR
- ✅ Behaviour-based detection (process trees, API calls)
- ✅ Forensics timeline you can query after an incident
- ✅ Rollback and containment from a central console
- ✅ Catches 0-days through anomaly detection
- ❌ Significantly more expensive
- ❌ Needs tuning and staff to respond to alerts
Which one do you need?
For a personal computer, the built-in AV (Windows Defender, XProtect) is enough if you keep your system patched and use a password manager. For a business of 10+ employees, AV alone is not enough — a managed EDR or MDR service is the baseline in 2026. For a regulated industry (health, finance, critical infra), EDR is effectively mandatory.
TL;DR — AV is the airbag, EDR is the dashcam plus crash investigator. Modern threats demand both; for individuals, the OS airbag is enough.
FAQ
Is Windows Defender a real antivirus?
Yes, and it consistently ranks near the top in independent tests. For most home users it is perfectly adequate.
Can I run AV and EDR together?
Most EDR vendors ship with their own AV module and explicitly disable others to avoid conflicts.
What about MDR and XDR?
MDR is "EDR with a 24/7 analyst service". XDR extends EDR signals across email, cloud and network into a unified view.