Updatable help was introduced with PowerShell 3. It gives authors the option to store the most recent versions of their help documentation outside of PowerShell on web servers.

Help for the core components of PowerShell is no longer a part of the Windows Management Framework package and must be downloaded before it can be viewed. The first time Get-Help is run, you will be prompted to update help.

If the previous prompt is accepted, PowerShell will attempt to download content for any module that supports updatable help.

Computers with no internet access or computers behind a restrictive proxy server may not be able to download the help content directly. The Save-Help command, which will be discussed later in this section, may be used to work around this problem. If PowerShell is unable to download help, it can only show a small amount of information about a command; for example, without downloading help, the content for the Out-Null command is minimal, as shown here:

PS> Get-Help Out-Null

NAME
    Out-Null
    
SYNTAX
    Out-Null [-InputObject <psobject>] [<CommonParameters>]
    

ALIASES
    None
    

REMARKS
    Get-Help cannot find the Help files for this cmdlet on this computer. 
    It is displaying only partial help.
        -- To download and install Help files for the module that 
           includes this cmdlet, use Update-Help.
        -- To view the Help topic for this cmdlet online, type: 
           "Get-Help Out-Null -Online" or go to
           http://go.microsoft.com/fwlink/?LinkID=113366. 

Updatable help as a help file may be viewed using the following command:

Get-Help about_Updatable_Help