HTML forms and PHP

Consider the following HTML code snippet for a form

<input type="text" name="name" id="id" value="value"/>

So, if we want to access the text from PHP, which one of these should we use?
The answer is "name". For example if we are using POST, then to access the text entered here,
we can use $_POST['name'].
The id is usually used to reference it in CSS and value is what is displayed on the screen.