What is the role of name="..." attribute in input?

Question

In this form code what is the role of name="" attribute?

name="s" and name="submit".

Is it necessary to add?

<form action="/index.php" method="get">
   <fieldset>
    <legend>Search</legend>
    <label for="s"><span>Search WaSP</span>
    <input value="" name="s" id="s"></label>
    <input type="submit" value="Go!" name="submit" >
   </fieldset>
  </form>

Answer 1

That is what's actually sent to the server as the name in a normal form submit.

E.g. the name of the StackOverflow answer field is post-text, so the name sent to the server for this field is post-text.

For a GET or application/x-www-form-urlencoded POST, this will be the left-side of a parameter (name=value).

Answer 2

The name ("control name") will be passed into the query string when the form is submitted. This is different from the id attribute which is used to identify an element uniquely by the UA (browser).

With name, the query will be like

/index.php?s=&submit=Go!

Without name, the query will be like

/index.php

Answer 3

This is how they are represented in the DOM as well.

document.forms[0].s.value