Drupal behaviors

Question

• What are Drupal behaviors at all?
• What type of service layer it offers to module developers?
• What type of relation it maps to jQuery.ready

Answer 1

Along with answers mentioned above on of the key things is you can pass data from php to javascript which is as follows

Passing values from PHP to Javascript with "Drupal.settings"

You can easily make variables from PHP available to Javascript on the front end with Drupal.settings using drupal_add_js() function

 array('key' => 'value')), 'setting');
?>

or

 'setting',
  'data' => array('myModule' => array('key' => 'value')),
);
?>

This will be available in Javascript as:

  if (Drupal.settings.myModule.key === 'value') {
    alert('Got it!');
  }