The Windows Server 2003 family consist of four distinct products:
Windows Server 2003, Standard Edition? The basic edition, replacing Windows 2000 Server.
Windows Server 2003, Enterprise Edition? The upscale edition with additional processor and memory support, clustering, and so forth. This edition replaced Windows 2000 Advanced Server.
Windows Server 2003, Datacenter Edition? Replaced Windows 2000 Datacenter Server as the top-end version of Windows.
Windows Server 2003, Web Edition? An entirely new edition, intended to compete with low-priced (and free) Web server operating systems such as Linux.
Although you can think of these editions in a tier, with Windows Server 2003, Web Edition at the bottom and Windows Server 2003, Datacenter Edition at the top, that's not really how Microsoft positions the products. True, Web Edition has less functionality than Datacenter Edition, but that's because Web Edition is designed for an entirely different purpose. Experienced Windows administrators often classify the server editions as "use the standard edition unless you need clustering, then use the advanced edition." Datacenter isn't usually considered by most administrators (for reasons we'll discuss later in this chapter), and Web Edition, of course, is an entirely new thing to deal with. Unfortunately, the "use standard unless you need clustering" doesn't really leverage the various editions' advantages very well, especially with Windows Server 2003, where the editions have definite advantages in different scenarios. So, as a Windows Server 2003 administrator, it is important that you choose the right edition of the product to meet your organization's needs.