User-Defined Aliases using PowerShell Profiles
A Profile is script that runs at startup of the session. The location of the Profile is stored in the $Profile variable, which by default is “My Documents\WindowsPowerShell\Microsoft.PowerShell_profile.ps1″
The Windows PowerShell profile is simply a script file that runs when Windows PowerShell starts up. You can put cmdlets, scripts, functions – any valid Windows PowerShell commands – into this script file. Each time you start Windows PowerShell, this script file will run. That means you can use the profile to set up your Windows PowerShell environment. Typically that would be custom console settings and aliases, but use your imagination and you can come up with other things you’d like to customize in PowerShell before you start working with it.