Write-Verbose

Write a string to the host's verbose display. This is normally used within PowerShell scripts to provide an optional message, normally hidden but available to view by setting a preference.

Syntax
      Write-Verbose [-message] string [CommonParameters]

Key
   -message string
       The message to display.
       {may be piped}

   CommonParameters:
       -Verbose, -Debug, -ErrorAction, -ErrorVariable, -WarningAction, -WarningVariable,
       -OutBuffer -OutVariable.

Setting the $VerbosePreference variable will alter the action of Write-verbose:

Continue Show the message on the console
SilentlyContinue do not show the message. [this is the Default action]
Stop show the message and then halt
Inquire prompt the user

Example

Write a message:

PS C:\> $VerbosePreference = "SilentlyContinue"
PS C:\> Write-Verbose "The quick red fox."

PS C:\> $VerbosePreference = "Continue"
PS C:\> Write-Verbose "The quick brown fox."

“Inebriated with the exuberance of his own verbosity, and gifted with an egotistical imagination” ~ Benjamin Disraeli

Related:

Write-Debug - Write a debug message to the host display
Write-Error - Write an object to the error pipeline.
Write-Host - Display objects through the host user interface
Write-Output - Write an object to the pipeline
Write-Progress - Display a progress bar
Write-Warning - Write a warning message