Bootstrap in Drupal
If you search for “drupal bootstrap” in Google, the first result will likely be the Bootstrap theme. This theme is the most popular on drupal.org with over 150,000 reported installs. But as of this writing, the theme only supports Bootstrap 3, not version 4 which is the latest.
So if you want to use Bootstrap 4 you’ll need to use another theme until the Bootstrap theme supports version 4.
In this tutorial, you’ll learn how to configure and use the Drupal 8 version of the Barrio theme which uses Bootstrap 4.