Check out the animated explanation for Twitter below to get a better idea of the videos on the site:
What is Twitter? - Explania
Everyone can benefit from using Explania because they have so many animations on such a wide variety of topics. The videos are short and you can even embed them onto a website if you wanted to share them with an entire class. If you are looking for other sites that offer video explanations of academic subjects you can also check out Qwiki and Common Craft.