Magento 2 have a good system for  organize the blocks by layouts, In Magento 2 that is more flexible . You can play by many ways .

We want show how the developers can play with all puzzles (layout block template and structure), the framwork Magento 2 have a component called View ("vendor/magento/framework/View"), it have almost all needed class for manage the frontend view in back and font office ,
 you can inject the class Magento\Framework\View\Layout  by factory for get instance of layout class . let's imagine your contruct  in plugin by example is :

 
    public function __construct(
      \Magento\Framework\View\LayoutFactory $layoutFactory
    ){
        $this->_layoutFactory= $layoutFactory;
    }
 

And use in your fucntion :

 
public function resolveLayot()
{
        $this->_layoutFactory
            ->createBlock('\MyVendor\MyModule\Block\Ship',
            'mycustom.block',
            ['data' => ['title' => "My Title"]]) ;
}
 

Let's translate all this lines to xml :

 
<block class="MyVendor\MyModule\Block\Ship" name="mycustom.block">
        <arguments>
        <argument translate="true" name="title" xsi:type="string">My Title</argument>
        </arguments>
</block>
 

You can add the template .phtml path just push inside your block  MyVendor\MyModule\Block\Ship  the parameters $template as :

 
protected $_template = 'MyVendor_MyModule::template.phtml';
 

But here is absolute declartion .  how you can tell to system where is the parent block or container ? Simple your should use the class structure Magento\Framework\View\Layout\Data\Structure inject it and you can use :

 
$this->structure->setAsChild('mycustom.block', 'product.info.details') ;
 

now you can call as child inside details.phtml for example .

Or you can use directly the object  $this->_layoutFactory   and use the method setChild($parentName, $elementName, $alias) . You can  use a lot of methods inside class layout getBlock($name) getXml() addContainer($name, $label, array $options = [], $parent = '', $alias = '') .

So other information:  "the class Structure register all map of child parent , and type of element block or container , and class layout .  use it for determinete the type of element with method isContainer($name) isBlock($name)" .