in Node.js - Will my main program be loaded as the first callback Function in the Events queue?

I see that Node.js, as part of executing the main program (say main.js) and initializing event loop- since my program will be wrapped inside a module Function by Node (if I am correct) - will this function be enQueued in the Event queue as the first callback , that would then be later/instantly picked up by the Event loop's poll cycle ? OR the Event loop will only start listening for Events after your program is executed/completed; and if some i/o calls were invoked in the main program - then the callbacks will be enQueued to the Event poll queue as and when

via Srini