There are a number of different default stylesheets and Javascript files which comes with your core WordPress install. These can be used at any time in your WordPress plugin or theme development, all you have to do is call wp_enqueue_style() or wp_enqueue_script() whenever you want to use these default styles or scripts.

The default scripts are:

Using Default Scripts

To use the default scripts all you have to do is use the function wp_enqueue_script() with the handle you want to call and any dependencies needed.

The below code snippet can be used to load the jQuery UI Javascript on the page.

<?php
function load_jquery_ui() {
    wp_enqueue_script('jquery-ui-core');            
}    
 
add_action('wp_enqueue_scripts', 'load_jquery_ui');
?>