Get-WSManInstance provides access to instances of resources at a lower level than commands such as Get-CimInstance.

For example, Get-WSManInstance can be used to get the WMI class Win32_OperatingSystem:

Get-WSManInstance -ResourceUri wmicimv2/win32_operatingsystem 

The response is an XmlElement that PowerShell presents as an object with properties for each child element.

Get-WSManInstance has been superseded by Get-CimInstance, which was introduced in PowerShell 3.0.