HTML5 is the next implementation of the HyperText Markup Language. In addition to many of the features of previous versions of HTML (and a few deprecations) it adds specific new features in its recommendation, including video capabilities and location-aware services. For example, you should be able to view a video without an additional plug-in, as well as "use your location" with a location-aware device. An example, if you're looking for movie theater showtimes, you could just click "View showtimes near me" instead of typing your city into a search box. As a cutting edge technology, it may be a while until it is fully implemented in some devices and browsers (such as Microsoft Internet Explorer).
I will post updates frequently on this new topic.