Endpoint Detection and Response (EDR) monitors laptops and servers for malicious behavior — not just known virus signatures — and can isolate a compromised device before ransomware spreads. Traditional antivirus misses fileless attacks and living-off-the-land techniques. EDR records process trees and network connections so analysts can roll back or contain threats. Microsoft Defender for Endpoint and other platforms integrate with Entra ID and SIEM. Deploy EDR on every managed endpoint, including remote Macs and PCs. Pair with MFA and patch management; EDR is most effective when the baseline hygiene is already solid.