HTML5 is just the next iteration of HTML. There are several new tags used for specific purposes. There are semantic tags such as the header, footer, article, and section tags which allow you to work with your layout in a more meaningful way.
There are some graphical tags such as SVG and canvas which allow us to draw things to our web page.
There are media elements such as audio and video which allows playing music and video directly without using insecure and unsupported technologies like Flash or Java applets. It also means we can reduce using iframes to stream content if we want.
Finally, there are new form element attributes such as number, date, time, calendar, and range. These form elements add more functionality to our forms without additional coding.