HTML source element

The <source> HTML element specifies one or more media resources for the <picture>, <audio>, and <video> elements. It is a void element, which means that it has no content and does not require a closing tag. This element is commonly used to offer the same media content in multiple file formats in order to provide compatibility with a broad range of browsers given their differing support for image file formats and media file formats.

The <source> element is a void element, which means that it not only has no content but also has no closing tag. That is, you never use </source> in your HTML.