The Loop

The Loop is PHP code used by WordPress to display posts. Using The Loop in WordPress we can display each post in the current page.

In wordpress have_posts() simply calls into $wp_query->have_posts() checks, if there are any posts exists or not.
And the_posts() simply calls $wp_query->the_posts(), which advances the loop counter and sets up the global $post variable as well as all of the global post data. Once we have exhausted the loop, have_posts() will return false and we are done.

Example:-

<?php while ( have_posts() ) : the_post(); ?>    
    <h2>
        <a href="<?php the_permalink(); ?>">
            <?php the_title(); // title of the post. ?> 
        </a>
    </h2>
    <small>
        <?php the_time('F jS, Y'); // time of the post ?>
    </small>

    <div>
        <?php the_excerpt(); // display unique content. ?>
    </div>
    <div class="entry">
        <?php the_content(); // whole content of the post. ?>
    </div>
<?php endwhile; ?>

Simple Example:-

Visit my next blog The Loop in WordPress -Part 2 to know about the_title(), the_time() the_content() the_excerpt() Loop in WordPress.