: The source URL. This tells the browser which specific page or video to load inside the frame.
frameborder: This attribute specifies the presence of a border around the iframe. A value of 0 means there will be no border. : The source URL
allowtransparency: Set to "true", this attribute allows the iframe to be rendered transparently, enabling the background of the parent page to be visible through transparent sections of the iframe's content. : The source URL
Best Practices for Iframe Usage