The Datacenter edition is the beefiest offering of Server 2012 and is designed for enterprises. If your organization is heavily dependent on virtualization and cloud deployments, then the Datacenter edition is the best option.

High availability is a key advantage with Datacenter because you can hot-add and hot-replace processors as well as hot-replace memory. “Hot” in this context refers to the ability to replace and add these components without needing to shut down the server.

Datacenter supports an unlimited number of virtual machines (VMs) running on up to two processors. In addition, Datacenter supports unlimited network and remote access connections; the number of connections is limited only by available network bandwidth and any hardware constraints. This is the edition to go with if your network needs enterprise-class virtualization and high scalability, because you can quickly expand the server to meet the demands of an organization that adds lots of users and resources such as data and devices.

Datacenter customers will typically purchase volume licenses. Volume licenses can also be purchased through Microsoft’s Software Assurance program. Licensing costs are based on the size of the business and number of PCs and devices that need to connect to the server. If your organization will use many virtual machines, needs a cloud-ready platform, and has hundreds of clients, your best option is the Datacenter edition.

The Standard edition of Server 2012 is suited for midsize organizations without heavy virtualization demands and those that run most business applications and systems onsite. Enterprise offers the same features as Datacenter, except you can run only up to two VMs on two processors.

Server 2012 Essentials is the server edition suited for smaller organizations (fewer than 25 PCs, devices, and/or end users). This edition does not offer Hyper-V, provides a limited-application server role, and offers no Windows Server Update Services (WSUS). Essentials can run on a server with up to two processors.

Foundation is a small-business edition that comes preinstalled only on servers targeted for the SMB (small to midsize business) market. It’s ideal for small businesses with no more than 15 users. Foundation does not include Hyper-V or Windows Server Update Services. It has partial or limited file services, network policy and access services, and limited remote desktop services.

If your organization has existing server licenses and CALs in place for legacy Windows Server, some of that licensing may be honored and applied to a Windows Server 2012 upgrade. Consult Microsoft’s Windows Server 2012 licensing FAQ to determine which licensing model your organization should go with.

2. Server 2012 Requirements

Server 2012 has specific hardware requirements for installation, despite the edition you are installing. Minimum requirements are:

Keep in mind, if you are installing Server 2012 on a system with more than 12 GB of RAM, you will need more than 32 GB of disk space for paging, hibernation, and dump files. You also will need more memory if you’re installing over a network.

Also, remember these are minimum requirements with no roles added to the installation. For the optimal installation experience, use the best hardware possible, and if you have to bump up any specification and are working within a limited hardware budget, splurge on the most memory you can. Currently, most servers—especially ones targeted to small to midsize businesses—ship by default with at least 2 GB of RAM.