There is a concept in PowerShell that is called Piping. It is a way to tell a command to use the result of the previous command. This can shorten your scripts since it requires less text and multiple commands can be written on a single line.
Here is an example for getting the list Documents from a site collection :
PS C:\> $srcList = Connect-Site -Url http://farm/sites/sitecollection | Get-List -Name Documents Id : ab6a768d-3478-4302-8258-53f2c2637c12 Title : Documents BaseType : Document Library Source : /sites/sitecollection/ ContentApproval : False RootFolder : /sites/sitecollection/Documents/ EnableAttachments : False EnableVersioning : True EnableMinorVersions : True ForceCheckout : False Site : http://farm/sites/sitecollection/