Microsoft’s Windows Server 2016 Standard :

Microsoft Windows Server Standard 2016 is the perfect streamlined solution for small-to-medium-sized businesses that operate in physical or minimally virtualised environments. The licence is core-based, so you must cover each physical core on the CPU.

• Nano Server Option: Opt for a streamlined server setup with restricted interfaces for heightened security against attacks.
• Azure Site Recovery Services: Available on Microsoft Azure, this feature facilitates real-time replication of your virtual machines (VMs) to an Azure backup vault.
• Volume Activation: Effortlessly activate licenses for multiple devices online.
• Cluster Rolling Upgrade: Upgrade cluster nodes’ operating systems seamlessly without interrupting Hyper-V or Scale-Out File Server workloads. It requires no additional hardware or new clusters and is reversible except for the “point-of-no-return.”
• Enhanced Domain, User, and Device Management: Aimed at optimizing Microsoft Windows Server 2016 usage, it supports larger deployments with multiple domains, domain controllers, and the ability to specify a designated domain controller.
• 2 Virtual Machines: The Standard edition permits limited virtualization, allowing users to create two virtual machines and one Hyper-V host.