Multi-DRM is protecting content once and issuing licenses across all three major DRM systems — Widevine, PlayReady, and FairPlay — so every device can play it. No single DRM covers every screen (Apple needs FairPlay, the Microsoft/TV world needs PlayReady, Android/Chrome needs Widevine), so any platform serving premium content to a real device matrix needs all three.
The elegant part is that you do not encrypt the content three times. Common Encryption lets one set of encrypted segments be unlocked by any of the DRMs; the platform packages once and the right license is fetched per device at playback time. Convergence on the cbcs scheme (required by FairPlay, now supported by Widevine and PlayReady) makes a single CMAF copy serve all three.
In practice multi-DRM is delivered by a multi-DRM service (in-house or a vendor like Axinom, EZDRM, BuyDRM, or a cloud provider) that exposes one license endpoint, maps each device to the correct DRM, and enforces a unified entitlement and policy model.
