Blocks, as the name suggests, are pieces of content that can be placed anywhere on your Drupal site. They can contain simple text, forms or something with complex logic.
In this tutorial, you’ll learn how to create a block using custom code and how to use Drupal Console to generate it. If you’ve used blocks in Drupal 7 then you will be familiar with the new interface in Drupal 8. If you’re a site builder, the whole process of creating, editing and deleting a block is very intuitive.
Before jumping into code, let’s talk about the Drupal Block UI and understand what has changed since Drupal 7.