Page to output sub-pages (children)

You can use for example very basic WP Query (or get_pages or what ever. this is just one example) (http://codex.wordpress.org/Class_Reference/WP_Query)

// The Query
$currentPageId = $post->ID; // get current page id inside loop
$args = array(
    'post_parent' => $currentPageId,
    'post_type' => 'page',
    'posts_per_page' => -1
    );
$query = new WP_Query( $args );

// The Loop
if ( $query->have_posts() ) {
    echo '<ul>';
    while ( $query->have_posts() ) {
        $query->the_post();
        echo '<li>' . get_the_title() . '</li>'; // this one outputs only title
    }
    echo '</ul>';
} else {
    // no posts found
}

/* Restore original Post Data */
wp_reset_postdata();

And there you have a list with titles for all the child pages of current page.