As discussed in the previous tutorial, one thing that affects markup in Drupal when using the Panels module is the Panels layout. In this tutorial, I will provide an overview of how layouts work in Panels. To learn more about how to create your own Panels layout in code, see the related tutorial: Adding Custom Panels Layouts in Your Theme. To learn how to use the Flexible Layout Builder in Panels, see this tutorial: Custom Panels Layouts.
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This video covers a topic in Drupal 7 which may or may not be the version you're using. We're keeping this tutorial online as a courtesy to users of Drupal 7, but we consider it archived.