1. Standard Edition: provides server functionality for most server role and features. It includes both full and Server Core installation options.
Suitable for small to medium company based at one location or with several branches that require basic server features and typical storage capacity.
2. Enterprise Edition: builds on Standard edition to provides greater scalability and availability. This edition also supports various enterprise technologies, such as clustering.
Standard edition has four x64 and four x86 sockets, the Enterprise edition has eight for each. Other features the Enterprise edition has that the Standard edition does not include are Hot Add Memory and Fault Tolerant Memory Sync. Enterprise edition allows unlimited network access connections and Terminal Services Gateway access. It comes with 4 virtual image use rights, whereas Standard edition comes with only 1.
Suitable platform for deploying business-critical application. Provides the foundation for a dynamic, scalable IT infrastructure. Improved availability through its clustering and hot-add processor capabilities, and improved security through consolidated identity management features. Can be used to consolidate applications with virtualization licensing rights, thus reducing infrastructure costs.
Suitable medium to large organization that is growing and that therefore requires maximum scalability. This edition is also suitable for organizations that require clustering technologies.
3. Datacenter Edition: has the same functionality as the Enterprise edition, but also provides support for additional memory and processors, and has unlimited virtual image use rights.
The main advantages of this edition include improved availability through clustering and dynamic hardware partitioning capabilities, and lower infrastructure costs. With this edition, you can scale from 2 to 24 processors.
Suitable for data center or telecommunications company that requires a reliable system with maximum storage capacity.
4. Webserver 2008 Edition: was created specifically to be used as a web and application server. Other server roles are not available in this edition.
Suitable for organizations that deploy web pages, sites, applications, and services to their users.
5. Windows Server 2008 for Itanium-based System edition: was created to be used with Intel Itanium 64-bit processors to provide web and application server functionality on that platform. This edition can be used for reduced instruction set computer (RISC)-based UNIX servers. Some server roles and features – for example Windows Media Services, Windows SharePoint Services, and file and print servers – may not be available in this edition.