Frage zu Costum Post Types

function post_type_posts() {
  register_post_type(
                'post',
                array(
                        'label' => __('Post'),
                        'public' => true,
                        'show_ui' => true,
                        'supports' => array('title', 'editor', 'thumbnail')
                )
        );
   register_taxonomy( 'cat', 'post', array( 'hierarchical' => true, 'label' => __('Kategorie') ) );
 }
add_action('init', 'post_type_posts');