How to create a node out of a webform submission?
The answer from @owenpm3 is great for adding this as an administrative duty. 

In order to automate this and make it occur on a successful submission, I would create a custom WebformHandler that you add to your form in the configuration settings, the same way you configure your form to send an email upon a successful submission. So under your web forms Settings tab, under the sub-tab: Emails / Handlers.

To build this you would need to create a custom module, mymodule and place the custom webform handler in: mymodule/src/Plugin/WebformHandler/

I will call the WebformHandler MyWebformHandler.php. Aside from this you will need an info file and that should do it.

Code for MyWebformHandler.php as follows:

&lt;?php

namespace Drupal\mymodule\Plugin\WebformHandler;

use Drupal\Core\Session\AccountInterface;
use Drupal\Core\Serialization\Yaml;
use Drupal\Core\Form\FormStateInterface;
use Drupal\node\Entity\Node;
use Drupal\webform\WebformInterface;
use Drupal\webform\Plugin\WebformHandlerBase;
use Drupal\webform\webformSubmissionInterface;
use Drupal\webform\Entity\WebformSubmission;


/**
 * Create a new Article node from a webform submission.
 *
 * @WebformHandler(
 *   id = "article_from_webform",
 *   label = @Translation("Create a node on submit"),
 *   category = @Translation("Content"),
 *   description = @Translation("Creates a new Article node from Webform Submissions."),
 *   cardinality = \Drupal\webform\Plugin\WebformHandlerInterface::CARDINALITY_UNLIMITED,
 *   results = \Drupal\webform\Plugin\WebformHandlerInterface::RESULTS_PROCESSED,
 *   submission = \Drupal\webform\Plugin\WebformHandlerInterface::SUBMISSION_REQUIRED,
 * )
 */

class MyWebformHandler extends WebformHandlerBase {

  public function submitForm(array &amp;$form, FormStateInterface $form_state, WebformSubmissionInterface $webform_submission) {

    // Get an array of form field values.
    $submission_array = $webform_submission-&gt;getData();

    // Dump the $submission_array to acquire the fields if you don't know what fields you're working with. 

    // Prepare variables for use in the node.  
    $title = $submission_array['subject'];
    $body = "&lt;p&gt;" . $submission_array['name'] . "&lt;br/&gt;";
    $body .= $submission_array['email'] . "&lt;/p&gt;";
    $body .= $submission_array['message'];

    // Create the node.
    $node = Node::create([
      'type' =&gt; 'article',
      'status' =&gt; FALSE,
      'title' =&gt; $title,

      'body' =&gt; [
        'value' =&gt; $body,
        'format' =&gt; 'basic_html',
      ],

    ]);

    // Save the node. 
    $node-&gt;save();
  }
}