Use the HTML or <audio> element to embed video/audio content in a document. The video/audio element contains one or more video/audio sources. To specify a source, use either the src attribute or the <source> element; the browser will choose the most suitable one.

Audio tag example:

<!-- Simple video example -->
<video src="videofile.webm" autoplay poster="posterimage.jpg">
  Sorry, your browser doesn't support embedded videos, 
  but don't worry, you can <a href="videofile.webm">download it</a>
  and watch it with your favorite video player!
</video>

<!-- Video with subtitles -->
<video src="foo.webm">
  <track kind="subtitles" src="foo.en.vtt" srclang="en" label="English">
  <track kind="subtitles" src="foo.sv.vtt" srclang="sv" label="Svenska">
</video>
<!-- Simple video example -->
<video width="480" controls poster="https://archive.org/download/WebmVp8Vorbis/webmvp8.gif" >
  <source src="https://archive.org/download/WebmVp8Vorbis/webmvp8.webm" type="video/webm">
  <source src="https://archive.org/download/WebmVp8Vorbis/webmvp8_512kb.mp4" type="video/mp4">
  <source src="https://archive.org/download/WebmVp8Vorbis/webmvp8.ogv" type="video/ogg">
  Your browser doesn't support HTML5 video tag.
</video>

Audio tag example:

<!-- Simple audio playback -->
<audio src="http://developer.mozilla.org/@api/deki/files/2926/=AudioTest_(1).ogg" autoplay>
  Your browser does not support the <code>audio</code> element.
</audio>

<!-- Audio playback with captions -->
<audio src="foo.ogg">
  <track kind="captions" src="foo.en.vtt" srclang="en" label="English">
  <track kind="captions" src="foo.sv.vtt" srclang="sv" label="Svenska">
</audio>

HTML5 provides a new standard for embedding an audio file on a web page.

You can embed an audio file to a page using the <audio> element:

<audio controls>
  <source src="file.mp3" type="audio/mpeg">
Your browser does not support the audio element.
</audio>

You can embed also a video to a webpage using the <video> element:

<video width="500" height="700" controls>
  <source src="video.mp4" type="video/mp4">
Your browser does not support the video tag.
</video>

Adding a video that will autoplay on a loop and has no controls or sound. Perfect for a video header or background.

<video width="1280" height="720" autoplay muted loop poster="video.jpg" id="videobg">
  <source src="video.mp4" type="video/mp4">
  <source src="video.webm" type="video/webm">
  <source src="video.ogg" type="video/ogg">
</video>

This CSS provides a fallback if the video cannot be loaded. Note that is it recomended to use the first frame of the video as the poster video.jpg.

#videobg {
  background: url(video.jpg) no-repeat;
  background-size: cover;
}