The CmdletBinding attribute is used to turn a function into an advanced function. Advanced functions were introduced with PowerShell 2.

CmdletBinding may be used to do the following:

• Access common parameters, such as ErrorAction, Verbose, and Debug
• Gain access to the built-in pscmdlet variable
• Declare support for WhatIf and Confirm and define the impact level of the command

If a script or function has no parameters, and wishes to make use of the capabilities of CmdletBinding, an empty param block must be declared:

function Test-EmptyParam {
    [CmdletBinding()]
    param ( )
}