What is Windows Power Shell & how it differs from CMD

Windows PowerShell is a task automation and configuration management framework from Microsoft, consisting of a command-line shell and associated scripting language built on the .NET Framework.
If it sounds complicated you can think it as same as the CMD prompt but with more advance tools.
PowerShell is a much more powerful command-line shell and scripting language than the Command Prompt is. It gives Windows system administrators a useful command-line environment.

There are some fabulous things that can be done using Power Shell

• perform your favorite CMD tasks
• Kill processes in power shell instead of using task manager
• Export NTFS file permossions
• Play with power sell 2.0
• Background a time consuming task
• Report all of the USB devices installed

( Read more about these tasks)

There are few main differences between cmd prompt and power shell

• Power sell uses a different set of commands called cmdlets.Many system administration tasks are exposed via Power Shell cmdlets
• PowerShell makes use of pipes, just as Linux and other Unix-like systems do. 
• You can create complex scripts for managing Windows systems much more easily than you could with the Command Prompt.

So here is why people use Power Sell over cmd prompt

• Cmd prompt is limited, can’t access many Windows system administration features.
• It is is more difficult to compose complex scripts with 

PowerShell is a new environment for Windows system administrators that allows them to use a more modern command-line environment to manage Windows.