Summary Of Blog Posts (Not Full)?

Hi,

I have set “Summary” in the settings in the WP admin area.

My index.php file:

<?php
get_header();
?>
<div id="main">
  <div id="content">
  	<h2><?php wp_title($display); ?></h2>
    <div id="blogHold">
    <?php if (have_posts()) : while (have_posts()) : the_post(); ?>
    <h3><?php the_title(); ?></h3>
    <h4>Posted on <?php the_time('F jS, Y') ?></h4>
    <p><?php the_content(__('(more...)')); ?></p>
    <hr>
    <?php endwhile; else: ?>
    <p><?php _e('Sorry, no posts matched your search criteria.'); ?></p>
    <?php endif; ?>
    </div>
  </div>

  <?php get_sidebar(); ?>

  </div>

<?php get_footer(); ?>

People say to use <?php the_excerpt(); ?> but I don’t understand how that works. Please help; https://rahulkhosla.co.uk

Thanks!