The most superficial ajax understanding of Drupal-process

1, the form inside the Ajax location of the form element has an event, fire system/ajax, corresponding to have Ajax_form_callback (), re-fetch to the form, and processing it, and rebuild it, and then use #ajax callback to process $ form, $form _state, and finally returns the new form render array, which is then rendered;

2, a href inside of the use-ajax, activate the corresponding Path menu item, and then partially refresh some data, and then return to the render array, and then be rendered

3, #states, according to the fixed format to ....

The most superficial ajax understanding of Drupal-process