HTML5 introduces several new semantic elements that help improve the structure and meaning of web pages. These include header, nav, article, section, aside, and footer. It also provides new form input types like date, time, email, url and new multimedia elements like video and audio. HTML5 aims to provide powerful APIs for building web applications using features such as canvas drawing, drag and drop, offline storage and native video playback in browsers. While HTML5 is still evolving, many of its features can be used now in modern browsers without waiting until full standardization and adoption is complete in 2022.