Windows PowerShell can be extended in several different ways. Typically, extensions are in the form of PowerShell snap-ins that add PowerShell providers to the working environment. The data that a provider exposes appears in a drive that you can browse. PowerShell V2 introduces module extensions, which must be imported before you use them.
Cmdlets that you’ll use to work with Windows PowerShell snap-ins, providers, and drives include:
Add-PSSnapin. Adds one or more registered snap-ins to the current session. After you add a snap-in, you can use the cmdlets and providers that the snap-in supports in the current session.
Add-PSSnapin [-PassThru] [-Name] Strings