This is among top 10 interview questions asked for Windows Server Administrator profile. Here I have summarized the difference between WIndows Server 2008 and Windows Server 2012 R2.Hope you find it useful.
Windows Server 2008 had two releases i.e 32 bit and 64 bit but Windows Server 2012 is only 64 but Operating System.
The Active directory in Windows Server 2012 has a new feature that allows you to add personal devices like tablets to the domain.
The Active directory recycle bin is another feature of windows Server which allows us to restore deleted AD objects using a GUI.
Windows Server 2012 has IIS version 8.0.
Windows Server 2012 uses Powershell version 3.0.
Server core was introduced in Windows Server 2008. Windows Server has additional feature that allows you to switch between Server core and GUI and vice versa.
Hyper-V in Windows Server 2012 has a feature called live migration which allows you to move virtual machine from one Hyper-V server to another Hyper-V Server while virtual machine is running. This feature was there in Windows Server 2008 but the virtual machine had to be clustered for migration to happen.
In Windows Server 2008 Hyper-V the merging of a snapshot in the virtual machine required the virtual machine to be turned off where as in windows Server 2012 it can be done while the machine is running.
In Windows Server 2008 Hyper-V the dynamic memory cant be given to the virtual machine is its running where as in Windows Server 2012 the running virtual machine can take dynamic memory from host while its running.