what is the difference HTML and html5

Answer 1

HTML 5 is the latest version of the HTML. It has come with many significant and big changes this time. http://www.w3schools.com/html/html5_intro.asp

Answer 2

HTML5 is the latest version of HTML. So, obviously it has more features. There's nothing like difference in Basic Language constructs, just more usability and simplicity. You can learn HTML and then the special features in HTML5.