Block types can be equated to Content types, since in Drupal 8, blocks are fieldable and utilize the same Field UI that we have experienced earlier when working with Content types. To get a closer look, begin by selecting the Block types tab from the Custom block library.

Currently we only have a single block type that Drupal gives us with the standard install, namely a Basic block.

The Basic block type contains a title and a body field and, just like that of a Basic page content type, the block is fieldable and can contain multiple form and display modes for presenting the content. Let's look at how we can manage the Basic block type by adding a new field.