Difference between Windows Server 2003 and Server 2008.

• Virtualization : Windows Server 2008 introduced Hyper-V (V for Virtualization) but only for 64 Bit Versions. More and more companies are seeing this as the way of reducing Hardware costs by running several Virtual servers on single physical machine.
  
  
  
  

• Server Core: It provides minimum installation required to carry out a specific server role such as for DNS, DHCP or Print Server.
  
  
  
  

• Better Security 

• Role Based Installation 

• RODC (Read Only Domain Controllers) : Read-only domain controllers (RODCs) are a new feature of Active Directory Domain Services (AD DS) in Windows Server 2008. RODCs are additional domain controllers for a domain that host complete, read-only copies of the partitions of the Active Directory database and a read-only copy of the SYSVOL folder contents.
  
  
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•  Enhanced Terminal Services 

• Network Access Protection : Microsoft's system for ensuring that clients connecting to server 2008 are patched, running a firewall.
  
  
  
  

• PowerShell : Microsoft's Command line shell and scripting language has provided popular with some server administrators.
  
  

• IIS7 : IIS 7.0 was a complete redesign and rewrite of IIS, and was shipped with Windows Vista and Windows Server 2008. IIS 7.0 included a new modular design that allowed for a reduced attack surface and increased performance. It also introduced a hierarchical configuration system allowing for simpler site deploys, a new Windows Forms-based management application, new command-line management options and increased support for the .NET Framework. IIS 7.0 on Vista does not limit the number of allowed connections as IIS on XP did, but limits concurrent requests to 10 (Windows Vista Ultimate, Business, and Enterprise Editions) or 3 (Vista Home Premium). Additional requests are queued, which hampers performance, but they are not rejected as with XP.
  
  
  
  

• Bitlocker : System Drive encryption can be sensible security measure for servers located in remote branch offices 
  
  
  
  
  
• Windows Aero : Windows Aero (a backronym for Authentic, Energetic, Reflective, and Open) is a set of interface and design guidelines that were introduced by the Windows Vista operating system. The changes made in the Aero interface affected many elements of the Windows interface and how it functions, including the incorporation of a new visual look, along with changes in interface guidelines reflecting appearance, layout, and the phrasing and tone of instructions and other text in applications.