Jean-Pierre Paradis's Blog: Announcing PSReadLine 2.1+ with Predictive IntelliSense | PowerShell

Tab completion has accelerated the success of new and experienced PowerShell users for over a decade. New users get the benefit of discovery, seeing available cmdlets and parameters as options while interactively typing. Experienced users receive the benefit of acceleration, typing less while using the Tab key to quickly complete a command.

Source : PowerShell