$$

Contains the last token in the last command received.

$?

Contains the execution status of the last command.

$^

Contains the first token in the last command received.

$_

Contains the current object being processed within a pipeline.

$Args

Contains an array of undeclared arguments received by function, script, or script block.

$Error

Contains an array of error objects recorded in the current shell session. The latest error can be accessed using the zero index of the array, that is, $error[0].

$Exbin

References the full path to the Exchange Server\Bin directory. This variable is only present when starting the shell using the Exchange Management Shell shortcut on a machine with the Exchange tools installed.

$ExScripts

References the full path to the Exchange scripts directory. This variable is only present when starting the shell using the Exchange Management Shell shortcut on a machine with the Exchange tools installed.

$False

Provides a Boolean false value when used in commands and scripts.

$ForEach

Contains the enumerator inside a ForEach-Object loop.

$Home

Contains the full path to the user's home directory.

$Host

Contains an object that represents the current PowerShell host application.

$Input

Contains the enumerator for items passed to a function. The $Input variable can access the current object being processed within a pipeline.

$MaximumHistoryCount

Specifies the maximum number of entries that can be saved in the command history in the current shell session.

$Null

Provides a NULL or empty value when used in commands and scripts.

$Profile

Contains the full path to the PowerShell profile for the current user and current host application.

$PSHome

Contains the full path to the installation directory of Windows PowerShell.

$Pwd

Contains the path to the current location.

$True

Provides a Boolean true value.