A cmdlet (pronounced "command-let") is a single-feature command that manipulates objects in Windows PowerShell. You can recognize cmdlets by their name format -- a verb and noun separated by a dash (-), such as Get-Help, Get-Process, and Start-Service.
In traditional shells, the commands are executable programs that range from the very simple (such as attrib.exe) to the very complex (such as netsh.exe).
In Windows PowerShell, most cmdlets are very simple, and they are designed to be used in combination with other cmdlets. For example, the "get" cmdlets only retrieve data, the "set" cmdlets only establish or change data, the "format" cmdlets only format data, and the "out" cmdlets only direct the output to a specified destination.
Each cmdlet has a help file that you can access by typing:
get-help <cmdlet-name> -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.