Windows Server 2016 Essentials is perfect for small companies with basic IT needs purchasing a first server, with a small or no dedicated IT department. It licenses customers for up to 25 users with one physical or virtual license, and has a simplified management interface on by default. The licensing for Essentials will continue to be a processor-based server model with no CAL requirements.
Windows Server 2016 Standard is for small businesses and customers that need advanced features, support for distributed office locations, and require a flexible way to virtualize their environment. It provides licensing for 2 VMs, unlimited number of user and devices with additional Client Access Licenses and unlimited number of Windows Server containers. New for Windows Server 2016 is the processor-core based licensing with the minimum of 16 core-license required but included in the base. Additional features, such as Storage Replica, Storage Spaces Direct, Shielded VMs and Host Guardian Service are reserved for the Datacenter Edition.
Windows Server 2016 Datacenter is for companies of all sizes that have demanding IT workloads, require advanced storage, and virtualization and application deployment. Among others, it includes unlimited VMs, unlimited Hyper-V containers, unlimited users and devices with additional Client Access Licenses. New for Windows Server 2016 is the processor-core based licensing with the minimum of 16 core-license required but included in the base. In addition to the core functionality, this edition includes features such as Storage Replica, Storage Spaces Direct, Shielded VMs and Host Guardian Service.
Note: With the introduction of Windows Server 2016, the Foundation edition has been discontinued for Windows Server 2016
Windows Server 2012 R2 Foundation is an economical, general purpose server for physical computing environments only. It provides customers with a Windows Server experience for up to 15 users. The licensing for Foundation will continue to be a server model with no CAL requirements.
Windows Server 2012 R2 Essentials is a cloud connected first server, ideal for small businesses with up to 25 users. It provides customers with the flexibility to have email in the cloud, run line of business applications, or run email on premises. The licensing for Essentials will continue to be a server model with no CAL requirements.
Windows Server 2012 R2 Standard is ideal for physical computing or lightly virtualized environments. It now provides customers with an additional virtual instance for a total of 2 virtual instances and all of the features, just like Datacenter edition. The licensing for Standard will change and adopt to the same model as Datacenter, of a processor plus CAL, where the license will cover up to two physical processors on a server.
Windows Server 2012 R2 Datacenter will continue to be the ideal edition for highly virtualized private and hybrid cloud environments. It provides customers with unlimited virtualization rights and all of the features of the product. The licensing for Datacenter will continue to follow a processor plus CAL model, however now, each license will cover up to two physical processors on a server.
Red Hat® Enterprise Linux® (RHEL) is an open source operating system designed for edge of network and core data center workloads. RHEL is a subscription-based operating system licensed in 2- and 4-socket versions. Within each socket licensing is an additional licensing option to choose one virtual image, four virtual images or unlimited virtual images to run on top. RHEL can be used in small, medium and large corporate and government organizations without additional licensing and comes in 1, 3- and 5-year subscriptions.
SUSE® Linux Enterprise Server (SLES) is an open source operating system designed to handle workloads running in large data center environments down to single-server environments. SLES is a subscription-based operating system that allows you access to patches, fixes and security updates through their customer portal. SLES has only one type of license that can be used on 1, 2- and 4-socket servers and can be purchased in 1 or 3-year subscriptions.