The Windows PowerShell engine implements a set of reserved parameter names, referred to as common parameters. All PowerShell cmdlets, including the PowerCLI cmdlets, support them.

Some of the PowerShell common parameters are Verbose, Debug, ErrorAction, ErrorVariable, OutVariable, and OutBuffer. For full list of the common parameters and more details on their usage, run Get-Help about_CommonParameters.

PowerShell offers two risk mitigation parameters: WhatIf and Confirm.

WhatIf

Allows you to see the effects of a command without running it.

Confirm

Prompts for your confirmation before running a command that stops a program or service or deletes data.