Custom Post Types — $args vs. labels array

Question

I registered a new post type, and I was wondering what the difference was between the $args and labels array. Read more about it in the codex (can't have more than two links, sorry).

For example, labels (code from this CPT tutorial)

'labels' => array(
    'name' => __( 'Super Dupers' ),
    'singular_name' => __( 'Super Duper' ),
    'add_new' => __( 'Add New' ),
    'add_new_item' => __( 'Add New Super Duper' ),
    'edit' => __( 'Edit' ),
    'edit_item' => __( 'Edit Super Duper' ),
    'new_item' => __( 'New Super Duper' ),
    'view' => __( 'View Super Duper' ),
    'view_item' => __( 'View Super Duper' ),
    'search_items' => __( 'Search Super Dupers' ),
    'not_found' => __( 'No super dupers found' ),
    'not_found_in_trash' => __( 'No super dupers found in Trash' ),
    'parent' => __( 'Parent Super Duper' ),
),

VS $args (code from this portfolio tutorial)

$args = array(  
        'label' => __('Portfolio'),  
        'singular_label' => __('Project'),  
        'public' => true,  
        'show_ui' => true,  
        'capability_type' => 'post',  
        'hierarchical' => false,  
        'rewrite' => true,  
        'supports' => array('title', 'editor', 'thumbnail')  
       ); 

What are the advantages of each? I noticed that if I tried to use some of the labels in the $args array, nothing happened or didn't happen as expected. For example, 'add_new_item' => __( 'Add New Super Duper' ), doesn't work if I include it in the $args array. I would like for those labels to work as well as all existing code in the $args array (i don't want anything to break).

Answer 1

The code you posted is an incomplete copy/paste of the code from the tutorial you linked. labels is a parameter within the $args array:

$labels_array = array(
    'name' => _x('Books', 'post type general name')
);

$args = array(
    'labels' => $labels_array
);

register_post_type( 'book', $args );

$args is an array that contains an array of label parameters.