1.2008 is combination of vista and windows 2003r2.
2. RODC one new domain controller introduced in it.[Read-only Domain Controllers.]
3.WDS (windows deployment services) instead of RIS in 2003 server
4. Shadow copy for each and every folders
5.Boot sequence is changed
5.Installation is 32 bit where as 2003 it is 16 bit as well as 32 bit, that’s why installation of 2008 is faster
6. Services are known as role in it
7. Group policy editor is a separate option in ads.
8. The main difference between 2003 and 2008 is Virtualization, management..
9.2008 has more inbuilt components and updated third party drivers Microsoft introduces new feature with 2k8 that is Hyper-V Windows Server 2008 introduces Hyper-V (V for Virtualization) but only on 64bit versions.
10.In Windows Server 2008, Microsoft is introducing new features and technologies, some of which were not available in Windows Server 2003 with Service Pack 1 (SP1), that will help to reduce the power consumption of server and client operating systems, minimize environmental byproducts, and increase server efficiency.
11.Microsoft Windows Server 2008 has been designed with energy efficiency in mind, to provide customers with ready and convenient access to a number of new power-saving features. It includes updated support for Advanced Configuration and Power Interface (ACPI) processor power management (PPM) features, including support for processor performance states (P-states) and processor idle sleep states on multiprocessor systems. These features simplify power management in Windows Server 2008 (WS08) and can be managed easily across servers and clients using Group Policies.
12. Many features are updated - as security, IIS and RODC.In security it enable outbound firewall as well as inbound, IIS 7 release, Read only Domain controllers.
14.Server Core provides the minimum installation required to carry out a specific server role, such as for a DHCP, DNS or print server.
15.Boot sequence is changed
16.Role-based installation or, services are known as role in it
18.Enhanced terminal services
19.Network Access Protection
20. Microsoft's system for ensuring that clients connecting to Server 2008 are patched, running a firewall and in compliance with corporate security policies.
24.System drive encryption can be a sensible security measure for servers located in remote branch offices.More and more companies are seeing this as a way of reducing hardware costs by running several 'virtual' servers on one physical machine. If you like this exciting technology, make sure that you buy an edition of Windows Server 2008 that includes Hyper-V, then launch the Server Manger, add Roles.
Windows Server 2008, formerly codenamed Longhorn, is no leas than 45 times faster than its predecessor, Windows Server 2003, in terms of network transfer speeds. Now whatever the perspective is on Microsoft's last 32-bit server operating system, the fact of the matter is that faster transfer speeds for of up to 45 times is quite an evolution compared to Windows Server 2003
25. Windows Aero
26.we can install windows 2008 server either in full version(install all services& applications) or server core(only install minimal required services), but in 2003 we can only install fully O.S.
27.Windows server 2008 use Hyper-V application & Roles concept for better productivity but server 2003 does not have such features.
28. Windows Server 2008, Active Directory has been renamed to Active Directory DomainServices (AD DS). AD DS retains the tools, architectural design, and structure that were introduced in Windows 2000 Server and Windows Server 2003, with some added improvements.
29.2003 was made to control XP networks.
30.2008 is made to control Vista networks.
31.The group policy and active directory schemas have been altered to include Vista polices.