PowerShell is built on top of the .NET Framework and replaces the old process of using text to pass data like the current CMD shell. PS is a scriptable language that provides an alternative to the manual changes you make through a GUI. It is more powerful than Perl or WSH, although those two technologies can help with automating a lot of tasks. Let’s look at what PS is and is not and hopefully it will help clear things up a bit.

Powershell

is NOT a programming languge like C## et al.
is a scripting language like VBS, WSH, Perl
is NOT a replacement for CMD.EXE - is an administrative tool
is NOT going to replace all your system administration tools
is going to change the way you administrate your network
(Source)

You can download powershell from here: http://www.microsoft.com/technet/scriptcenter/topics/msh/download.mspx

After installing it, go to start–> run –> powershell.

It even has same commands and looks of a linux shell:

List of some of it’s commands, you can seem by typing help on the shell prompt.

Using Unix shell like terminology:

Powershell is making it’s debut as part of an operating system in Windows Server 2008, Is this another step for MS towards server dominance? Even though they are happily copying Linux features in it’s commercial products.

http://www.iaps.com/2007-server-hardware-and-os-survey.html

Cheers,
Pavs