Get-Variable provides access to any variable that has been created in the current session as well as the default (automatic) variables created by PowerShell. For further information on automatic variables, see about_Automatic_Variables (Get-Help about_Automatic_Variables).

When using the *-Variable commands, the $ preceding the variable name is not considered part of the name.

Default or automatic variables often have descriptions; these may be seen by using Get-Variable and selecting the description:

Get-Variable | Select-Object Name, Description