The <video> element, which adds native video playback support to the HTML specification in HTML5, can be used to embed a video in an HTML document. Add the video URL to the element by using either the src attribute of the <video> element or by nesting one or more <source> elements between the opening and closing <video> tags.
The <track> element is used as a child of an <audio> or <video> element and adds a time-based data source to the parent media element. For example, the <track> element can be used to add timed subtitles to a video and closed captions to audio content.
The <source> element is used as a child of a <picture>, <audio>, or <video> element, and identifies the URL of one or more media resources. The <source> element is commonly used to add media resources in multiple formats for the best possible cross-browser compatibility.
The <section> element is a structural HTML element used to group together related elements. Each <section> typically includes one or more heading elements and additional elements presenting related content.