译-what is cmdlet

A cmdlet (pronounced "command-let") is a lightweight Windows PowerShell script that performs a single function. A cmdlet, which is expressed as a verb-noun pair, has a .ps1 extension.

Although Windows PowerShell includes more than two hundred basic core cmdlets, administrators can also write their own cmdlets and share them. Each cmdlet will have a help file that can be accessed by typing Get-Help CmdletName-Detailed.  The detailed view of the cmdlet help file includes a description of the cmdlet, the command syntax, descriptions of the parameters and an example that demonstrate use of the cmdlet.

Popular basic cmdlets include:

Cmdlet	Function
Get-Location	get the current directory
Set-Location	change the current directory
Copy-Item	copy files
Remove-Item	remove a file or directory
Move-Item	move a file
Rename-Item	rename a file
New-Item create a new empty file or directory	create a new empty file or directory

参考：

http://whatis.techtarget.com/definition/cmdlet