title: "__(" in custom post types
body: <p>I'm building my custom post types for a wordpress project, but I do not understand why in some examples over the internet it's possbile to find something like this:</p>
  
  <pre><code>register_post_type('omb_prodotti',
      array(
        'labels' =&gt; array(
          'name' =&gt; __( 'customposttype' ),
          'singular_name' =&gt; __( 'customposttype' )
        )
  </code></pre>
  
  <p>what is "__(" used for? Is it related to translations? Wouldn't it be possible to just write it like this instead:</p>
  
  <pre><code>register_post_type('omb_prodotti',
      array(
        'labels' =&gt; array(
          'name' =&gt; 'customposttype',
          'singular_name' =&gt; 'customposttype'
        )
  </code></pre>
  
  <p>Sorry but I'm a beginner in both PHP and building custom WP themes.</p>
  
  <p>Thank you very much.</p>