Doubt about Selector

Doubt about Selector

Hi

I saw this solution about 'hiding all input elements within a form'

HTML:


<body>
  <form  name='demo_form'>
  First name: <input type="text" name="fname"><br>
  Last name: <input type="text" name="lname"><br>
  <input type="submit" value="Submit">
  </form>
  </body>


Solution as i wrote: 

$(document).ready(function(){
  $ ("input").hide();
});

The above code worked, however the given solution was:

$ ( demo_form.elements ).hide();

I would like to know: Isn't 'elements' a generic selector?
isn't it more specific to use 'input'?
Also, how do you select the form by name?

Thanks a lot for helping me!

Jayashree