What is the difference between HTML and HTML5?

HTML5 is the fifth and current major version of HTML, introducing significant improvements over HTML 4. Key additions include semantic elements like <header>, <nav>, <article>, <section>, and <footer> that describe the purpose of content. HTML5 also introduced native support for audio and video (<audio>, <video>) without plugins like Flash, the <canvas> element for 2D drawing, Web Storage (localStorage/sessionStorage), Geolocation API, Web Workers, and improved form input types (date, email, range). HTML5 also removed deprecated presentational elements like <font> and <center>.