In this chapter, we will be diving into some of the great improvements that Drupal 8 has implemented, such as the introduction of better HTML5 support, which caused core maintainers to rethink how markup was being output by fields and templates. This resulted in allowing theme developers to control where to use semantic elements, support for ARIA roles to improve accessibility, simplified style and script elements, and the ability for input filters to accept HTML5 elements.
Also, the emphasis on responsive or a mobile first approach to how we use a content management system resulted in a whole rewrite of the theme system and the introduction of Twig. This rewrite included both the Bartik and Seven themes, which are now responsive and allow for content to flow based on the device we happen to be viewing Drupal 8 on.
Finally, the way site builders...