what is the machanism behind the public static void main(String args[])?

Answer 1

Actually it is the same mechanism as a function F(x) is using from the main, the only difference is that in this case the operating system have to pass the parameters to the main (This is called ABI, look for it in goggle - it vary from one architecture to another and from one programing language to another. It can use stack or register to pass parameters etc). so to know it you have to define what architecture you are using (probably Intel) and which programing language you are using.