HTML5 is the most recent edition of Hypertext Markup Language. It is at present not supported by all browsers. Only a few browsers support it. In fact the real idea behind HTML5 is that it is not a single big entity but is formed of a number of small parts. These works together help to generate something, which is groundbreaking as well as highly developed and not all the features of HTML5 are supported by all the browsers so it is for you to find out which feature you want and which feature your browser supports.