Get-Alias cmdlet gets the aliases in the current session. This includes built-in aliases, aliases that you have set or imported, and aliases that you have added to your Windows PowerShell profile.
By default, Get-Alias takes an alias and returns the command name. When you use the Definitionparameter, Get-Alias takes a command name and returns its aliases.
what is % and ? in Powershell alias
% - foreach-object
? - Where-object
