What use is ‘docking’ as opposed to an application just immediately starting?

You can script when a VAA is docked.  So, for example, if there’s a specific configuration item that your app needs to know about when it’s moved to a new environment, that could be scripted here.  For instance, if an app wants to have the machine IP address in a registry entry, you can write a little script that catches the machine IP address and write it into the VAA at docking – into that part of the registry.  And, of course, if the VAA were to be moved, that script would be run again and you’d automatically have the new IP address in it.  So there are things like that that are really handy to do to accommodate an application’s configuration requirements.  Scripting is especially useful when you move an app to a new environment.  There is a Run command that is also useful in automation.  You can say on the command line, “Dock.  Run”.  If it’s a database server everything runs immediately.