This is a Microsoft Windows Server 2025 Datacenter Additional License, sold as a reseller point-of-sale licence with no physical media or product key box included - the licence entitlement itself is the product. It covers an additional 16 CPU cores under Datacenter edition, Microsoft's top Windows Server tier aimed at heavily virtualised environments: it grants unlimited Windows Server virtual machine instances per licensed host, plus Datacenter-exclusive features such as Storage Spaces Direct, Storage Replica, and Shielded VMs. This SKU is an incremental core-pack addition rather than a full server licence, used by businesses expanding an existing Datacenter-licensed host's core count - for example after a CPU or server upgrade - rather than standing up a brand-new licensed server.