PowerShell cmdlets return (active) objects in the same process space as the hosting process (usually the shell). As such they can expose expensive-to-compute properties as late-evaluated properties that are only evaluated if and when they are invoked later.

Take for instance Get-Process:

    $p = ps powershell

(ps is an alias for Get-Process). Now $p is the process information onject about the PowerShell process itself.

Type

    $p

And PowerShell will respond with

    Handles  NPM(K)    PM(K)      WS(K) VM(M)   CPU(s)     Id ProcessName
    -------  ------    -----      ----- -----   ------     -- -----------
        359      24    57096      61972   611     2,20   9608 powershell

If you request the content of $p at some later point in time, you will notice how the CPU has increased, for instance. The point is that a lot of the properties are computed when read, and hence do not incur overhead in the pipeline.