How does clicking on a desktop icon run a program ?
 

I have studied scripts associated with a desktop icons and cannot understand how this causes programs to run when the icon is clicked.
I would appreciate an explanation as to what exactly happens or where I can find this.

Thanks in anticipation

X receives the click on the desktop "window" and passes the click to the application owning this "window" (Nautilus, Rox…). The application detects that the click occured on a launcher and finds in this launcher's description the command that should be run when the launcher is triggered. The command is launched in the background as a separate process.

Yves.