Iz wiki :>
Microsoft released various editions of Windows 2000 for different markets and business needs: Professional, Server, Advanced Server and Datacenter Server. Each was packaged separately.
Windows 2000 Professional was designed as the desktop operating system for businesses and power users. It is the client version of Windows 2000. It offers greater security and stability than many of the previous Windows desktop operating systems. It supports up to two processors, and can address up to 4 GB of RAM. The system requirements are a Pentium processor of 133 MHz or greater, at least 32 MB of RAM, 650 MB of hard drive space, and a CD-ROM drive (recommended: Pentium II, 128 MB of RAM, 2 GB of hard drive space, and CD-ROM drive).[81]
Windows 2000 Server SKUs share the same user interface with Windows 2000 Professional, but contain additional components for the computer to perform server roles and run infrastructure and application software. A significant new component introduced in the server SKUs is Active Directory, which is an enterprise-wide directory service based on LDAP. Additionally, Microsoft integrated Kerberos network authentication, replacing the often-criticised NTLM authentication system used in previous versions. This also provided a purely transitive-trust relationship between Windows 2000 domains in a forest (a collection of one or more Windows 2000 domains that share a common schema, configuration, and global catalog, being linked with two-way transitive trusts). Furthermore, Windows 2000 introduced a Domain Name Server which allows dynamic registration of IP addresses. Windows 2000 Server supports up to 4 processors, requires 128 MB of RAM and 1 GB hard disk space, however requirements may be higher depending on installed components.[81]
Windows 2000 Advanced Server is a variant of Windows 2000 Server operating system designed for medium-to-large businesses. It offers clustering infrastructure for high availability and scalability of applications and services, including main memory support of up to 8 gigabytes (GB) on Physical Address Extension (PAE) systems and the ability to do 8-way SMP. It supports TCP/IP load balancing and enhanced two-node server clusters based on the Microsoft Cluster Server (MSCS) in Windows NT Server 4.0 Enterprise Edition.[82] Limited number of copies of an IA-64 version, called Windows 2000 Advanced Server, Limited Edition were made available via OEMs. System requirements are similar to those of Windows 2000 Server [81], however they may need to be higher to scale to larger infrastructure.
Windows 2000 Datacenter Server is a variant of Windows 2000 Server designed for large businesses that move large quantities of confidential or sensitive data frequently via a central server.[83] Like Advanced Server, it supports clustering, failover and load balancing. Its minimum system requirements are normal, but it was designed to be capable of handing advanced, fault-tolerant and scalable hardware—for instance computers with up to 32 CPUs and 64 GBs RAM, with rigorous system testing and qualification, hardware partitioning, coordinated maintenance and change control. Limited number of copies of an IA-64 version, called Windows 2000 Datacenter Server, Limited Edition were made available via OEMs. System requirements are similar to those of Windows 2000 Advanced Server [81], however they may need to be higher to scale to larger infrastructure.
.
