Refresher course on the steps on the use of a win app and/or mdi child form

Question

What is the behaviour of a mdi child form that is called over and over? The mdi child form has an augmented InitializeComponent(), it looks like this:

public Indiv_Truck_Cntrl()

{

//public string UserHostAddress { get; }

InitializeComponent();

//Primes setting for the first use

INITIAL_SET();

//need to check RS232 port for condition; done in mainController

//SerialStart_Check();

//timer setup , comment out when using as child mdi

// System.Timers.Timer Send_timer = new System.Timers.Timer();

//Send_timer.Elapsed += new ElapsedEventHandler(SEND_SETTINGS_Click);

}

Question One: when a/this form is made for the for the first time how much of the above code is done and how much is considered part of the initialize process.

Question Two: How does the app know what part of the code is not to be reinitialized. In other words what part of the program is to done everytime it is called? Or does the INITIAL_SET(); get done everytime the form gets summoned or refreshed?

Question Three: Does a piece of code need to be design first before its used or doe it matter.

Thanks

N.