Support for oEmbed opens up wealth of opportunities for embedded content
Drupal 8.6.0 has an out-of-box adds support for embedding remote YouTube and Vimeo videos by means of the oEmbed format. You may notice these are often encapsulated in an iframe. You can see this evident in a new media type being defined called 'Remote Video' available form /admin/structure/media. A new icon is also available form your wysiwyg that allows you to embed the new format in your page or block.