HTML5 Multimedia Reference

 src="video.mp4" controls> # basic video
 width="640" height="360"> # set dimensions
   src="video.mp4" type="video/mp4">
   src="video.webm" type="video/webm">
 # multiple formats

 autoplay> # auto play video
 loop> # loop continuously
 muted> # mute audio
 poster="thumbnail.jpg"> # preview image
 preload="auto"> # preload video
 controls> # show controls

 src="song.mp3" controls> # basic audio
 autoplay loop> # auto play & loop
   src="song.mp3" type="audio/mpeg">
   src="song.ogg" type="audio/ogg">
 # multiple formats

 src="photo.jpg" alt="Description"> # basic image
 width="300" height="200"> # set dimensions
 loading="lazy"> # lazy loading

 # responsive images
   srcset="large.jpg" media="(min-width: 800px)">
   src="small.jpg">

 src="page.html"> # embed page
 width="560" height="315" # YouTube video
  src="https://youtube.com/embed/ID"
  frameborder="0" allowfullscreen>

 src="file.pdf" type="application/pdf"> # embed PDF