Who can explain these paragraphs for me?

I'm reading the helloworld tutorial. I can't understand the following paragraphs in http://docs.elgg.org/wiki/Tutorials/HelloWorld because of my weak programming foundation.  Could somebody please explain them more clearly for me? Many thanks.

Three variables are being passed to the input/text view: the name of the form input text box, a default value, and the css class that is assigned to the text box. The name of the input text box is params[message] because Elgg will automatically handle widget variables put in the array params. The actual php variable name will be message.

The reason we set the 'value' index of the array is so that the edit view remembers what the user typed in the previous time he changed the value of his Message text. This is done through the $vars array. Every view is passed the array $vars. This array contains all the variables the view needs. In this case, we are using the entity object that was passed to the edit view. This is an instance of the ElggWidget class that represents our widget. We are using the metadata variable message. Notice the relationship between the names of the internalname variable and the value.

Now to display the user's message we need to modify view.php to use this message variable. Edit view.php and change it to:

<div class="contentWrapper">
<?php echo $vars['entity']->message; ?>
</div>
  • i don't understand too.

    The name of the input text box is params[message] because Elgg will automatically handle widget variables put in the array params. The actual php variable name will be message