bogdan

Embeds are needed to embed video from youtube or to embed Google Map or just to embed content from external page. 
WordPress removes embed when you switch from “HTML” to “Visual” tab because of the security reasons. 
So you can embed object code using this shortcode <code>[iframe src="http://player.vimeo.com/video/3261363" width="100%" height="480"]</code>.

iframe to embed

Embeds are needed to embed video from youtube or to embed Google Map or just to embed content from external page.

Kodetop

WP Youtube Player allow insert Youtube videos on WordPress using a single quicktag <code>[tube][/tube]</code>
Features
<ul>
<li>Easy install</li>
<li>Embed Youtube movies with simple code</li>
<li>Panel for easy configuration</li>
<li>Config Player version (AS2 & AS3)</li>
<li>Support config themes for player</li>
<li>Support HTML5 Player</li>
<li>Support tubePlayer (http://blog.unijimpe.net/tubeplayer/) for play videos.</li>
<li>Generate <code><object></code> code for Feed compatibility </li>
<li>Generate <code><object></code> code optimized for iPhone</li>
</ul>
For insert single youtube video on Post Content or Text Widget you can use ‘Youtube URL’, ‘Youtube Embed URL’ or ‘Youtube Video ID’:
<pre><code>[tube]http://www.youtube.com/watch?v=AFVlJAi3Cso[/tube]

[tube]http://www.youtube.com/v/AFVlJAi3Cso[/tube]

[tube]AFVlJAi3Cso[/tube]
</code></pre>
To insert video with specific size can user width and height:
<pre><code>[tube]http://www.youtube.com/watch?v=AFVlJAi3Cso, 500, 290[/tube]
</code></pre>
To insert video on template, use the php code:
<pre><code><?php wp_youtubeplayer("movie.swf", "width", "heigth"); ?>
</code></pre>
For more information visit <a href="http://blog.unijimpe.net/wp-youtube-player/" title="plugin website" rel="nofollow ugc">plugin website</a>

iframe to embed vs WP YouTube Player