The three editions at a glance
Standard and Datacenter share the same core-based licensing model and differ mainly in the permitted number of virtual instances. Essentials is a standalone edition for small environments; it works without separate access licences.
| Edition | Characteristics | Suitable for |
|---|---|---|
| Windows Server Standard | Two virtual instances per licence, core-based | SMBs with limited virtualisation |
| Windows Server Datacenter | Unlimited virtual instances, core-based | Virtualisation-intensive environments, data centre |
| Windows Server Essentials | One server, up to 25 users, no separate CALs | Small businesses with a single server |
What a complete server licence includes
- The server edition. Standard, Datacenter or Essentials, matched to your virtualisation requirements.
- Core-based licensing. With Standard and Datacenter, licensing is based on physical processor cores, with a defined minimum purchase per server.
- Client Access Licenses (CALs). With Standard and Datacenter, every accessing user or device needs a CAL. Essentials is exempt from this.
- RDS CALs where needed. Anyone using Remote Desktop Services additionally needs RDS CALs, separate from the standard CALs.



