Magento 2 CMS blocks are managed directly from Magento admin using widgets / WYSWYG editor widgets and displayed on any page of your Magento 2 store. Except for displaying CMS block on CMS Page or CMS Block, showing it on category page there is an option to call CMS block programmatically using XML file.

Use this code in order to add the CMS block using Magento 2 layout XML:

<referenceContainer name="content">
  <block class="Magento\Cms\Block\Block" name="unick_block_name">
      <argument name="block_id" xsi:type="string">my_cmsblock_identifier</argument>

You need to replace "my_cmsblock_identifier" with your CMS block Identifier or ID (we recommend to use Identifier).