Script, or "cmdlet," used by Windows PowerShell, a Windows shell program built on Microsoft's .NET Framework; contains a series of lines written in the PowerShell scripting language; similar to a .BAT or .CMD file, but executed by Windows PowerShell instead of the Windows CMD.EXE and COMMAND.COM programs.
Cmdlets can be used to automate Windows tasks. For example, a cmdlet may rename a group of files to use a new file extension. Another cmdlet may examine the Windows registry and output results to a file. Cmdlets also support aliases, pipelines, and named and positional parameters for commands.
Windows PowerShell is installed by default on Windows 7.
NOTE: Be careful when executing PS1 scripts since they may contain functions that access critical Windows operating system components.