Windows Server 2003 is available in the following four editions:
Standard Edition: Standard Edition is intended for file-and-print services and general purpose application support. It can also act as an Internet gateway and dial-in server.
Enterprise Edition: Enterprise Edition has greater memory and processor capacity than Standard Edition, along with support for clustering and advanced certificate services. It is intended for high-end applications and high-availability services. It also supports services that are no longer included in the Standard Edition package.
Datacenter Edition: Datacenter Edition comes as part of a hardware/software package supplied by authorized hardware vendors. Datacenter Edition has more memory and clustering capacity than Enterprise Edition and contains features that support superior availability. Datacenter Edition is suitable for large, critical datacenter applications.
Web Edition: Web Edition is a new addition to the Windows server family which is specially made for web services and web hosting applications. Web Edition lacks many of the features in the Standard Edition. But Web Edition is priced less than other editions.