What are the different editions of Windows Server 2008?

The entry-level version of Windows Server 2008 is the Standard Edition. The Enterprise Edition provides a platform for large enterprise wide networks. The Data center Edition provides support for unlimited Hyper-V virtualization and advanced clustering services. The Web Edition is a scaled-down version of Windows Server 2008 intended for use as a dedicated web server. The Standard, Enterprise, and Data center Editions can be purchased with or without the Hyper-V virtualization technology.