Cmdlets are specialized commands in the PowerShell environment that implement specific functions. These are the native commands in the PowerShell stack. Cmdlets follow a Verb-Noun naming pattern, such as Get-ChildItem, which makes it self-documenting code. Cmdlets output their results as objects and can also receive objects as input, making them suitable for use as recipients in a pipeline. If a cmdlet outputs multiple objects, each object in the collection is passed down through the entire pipeline before the next object is processed.（维基百科）