custom wordpress loop

You'll learn more about the WordPress Loop with the WordPress Theme Development course. I believe this course is part of the Learn WordPress track which doesn't go into back end coding of WordPress. :-)

The loop is used to return posts, the basic syntax can be found here: https://codex.wordpress.org/The_Loop . This article should give you a lot of examples of ways to use the loop to retrieve different data. You can also create a custom loop to retrieve different post types and refine the results further.

A basic loop that retrieves the 4 most recent posts with the posts title, content, date and author will look like this:

<?php 
$args = array(
    'post_type' => 'post',
    'posts_per_page' => 4
);
$loop = new WP_Query( $args );
if ( $loop->have_posts() ) {
    while ( $loop->have_posts() ) {
        $loop->the_post(); // returns the post
        the_title(); // echos the title
        the_content(); // echos the content
        the_author(); // echos the author
        the_date(); // echo the date
    } // end while
} // end if
?>

You don't need any programming experience in PHP to understand what a loop is. Think of it as a roller coaster.

For example lets compare WordPress blog posts to a roller coaster that allows 1 person on at a time. There is 5 people waiting in line for the roller coaster with the loop. Each one of those 5 people will ride the roller coaster and do the loop 1 time. Once a passenger exits the roller coaster the next passenger will get on. In WordPress 5 blog post would be like the 5 people and showing all 5 posts on your blog to the visitor would require each blog post going around the loop 1 time. Once the first blog finishes the loop the next 4 will go one at a time until its done and its showing all 5 posts.