WordPress at a glance
action is not described

admin_enqueue_scripts action-hook . WP 1.0

This action is documented in wp-admin/admin-header.php

Usage

add_action( 'admin_enqueue_scripts', 'action_function_name_9675' );
function action_function_name_9675( $string ){
	// action...
}
$string
-

Where the hook is called

WP_Customize_Widgets::enqueue_scripts()
admin_enqueue_scripts
iframe_header()
admin_enqueue_scripts
wp_iframe()
admin_enqueue_scripts
wp-includes/class-wp-customize-widgets.php 680
do_action( 'admin_enqueue_scripts', 'widgets.php' );
wp-admin/includes/template.php 2031
do_action( 'admin_enqueue_scripts', $hook_suffix );
wp-admin/includes/media.php 538
do_action( 'admin_enqueue_scripts', 'media-upload-popup' );
wp-admin/admin-header.php 102
do_action( 'admin_enqueue_scripts', $hook_suffix );

Where in WP core the hook is used WordPress

wp-includes/class-wp-customize-widgets.php 93
add_action( 'admin_enqueue_scripts', array( 'WP_Internal_Pointers', 'enqueue_scripts' ) );
wp-includes/class-wp-customize-widgets.php 51
add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_scripts' ) );
wp-includes/class-wp-customize-widgets.php 424
add_action( 'admin_enqueue_scripts', 'wp_auth_check_load' );
wp-includes/class-wp-customize-widgets.php 472
add_action( 'admin_enqueue_scripts', '_wp_customize_loader_settings' );
wp-includes/class-wp-customize-widgets.php 508
add_action( 'admin_enqueue_scripts', 'wp_localize_jquery_ui_datepicker', 1000 );
wp-includes/class-wp-customize-widgets.php 510
add_action( 'admin_enqueue_scripts', 'wp_common_block_scripts_and_styles' );