The optional Media Embed and Semantic Media Embed plugins, introduced in CKEditor 4.5, allow to embed resources (videos, images, tweets, etc.) hosted by other services (called the "content providers") in the editor.
By default the plugins use the Iframely proxy service which supports over 1715 content providers such as YouTube, Vimeo, Twitter, Instagram, Imgur, SlideShare, or Google Maps, but you can configure the widgets to use another proxy service of your choice.
When either Media Embed or Semantic Media Embed plugin is enabled, thebutton is automatically added to the toolbar. Once clicked, it opens the Media Embed dialog window that lets you add the URL of the resource to be embedded. You can also paste that resource's URL into the editor content and it will be automatically embedded if the optional Auto Embed plugin is enabled.
The sample below uses the Media Embed plugin together with the Auto Embed and Enhanced Image plugins. Additional widget styles are defined to control widget size and alignment.
Try embedding more resources like the following. You can either paste these URLs into the editor or use the Media Embed dialog.