what's the different between calling functions with () or without ()

what's the different between calling functions with () or without ()

hi , i have really big problem in understanding this .

let say i have an object and my objects contain couple of functions 

var my_methods = {

      init:function(){
      
            $(window).load(my_methods.create_element());
            $(window).click(my_methods.window_clicking);      
      
      },
      create_element:function(){
            //some code
      },
      window_clicking:function(){
            alert('hello world');
      }
}

the both of the above functions calling w'll works pretty fine , but the problem is that if i'm using () it w'll call the function like calling function's simply but if i don't use () (in second line) it w'll not calling the function it'll attach the handler to the event .

so if i use 

 $(window).click(my_methods.window_clicking());

it'll works just for one time and trigger out immediately.

is my explanation correct or i'm a little wrong . of what i.m saying.
and i'll thank you if you show me example .