Dynamic media is incorporated in a Web page in the same two main ways images are, which are through hyperlinking and embedding. When a dynamic media is linked to, the browser uses a helper application, which is separate from a Web page, to play it, and when it is embedded, it plays within the page, typically using a plug-in. Both delivery methods can be accomplished using HTML elements. It is also possible to combine HTML with Flash technologies to deliver dynamic media, but this is discouraged, as the use of Flash technologies for delivering media on the Web is all but obsolete. For this reason, how to add Flash media objects to a Web page is not discussed in detail in this text. Tutorials on this can be found at the website for Adobe Flash (now known as Animate CC).
Although adding dynamic media to a Web page can be as straightforward as adding a static image, an important practical thing to know is that the result is not always predictable, as different browsers and hardware (such as PC, Mac, iPhone and iPad) do not all support the same technologies. For example, the newer HTML elements (i.e., <audio> and <video>) do not work in old browsers and not all media file formats are supported by every browser. Because of these incompatibilities, delivering dynamic media successfully on a Web page requires extra considerations in order to ensure that a media file works on as many systems as possible. Often this means using multiple methods to deliver the same file as well as providing the same media in different file formats. How this is done for audio, video, and animation, using HTML, is dealt with here.
Source: Sklar David (2016), HTML: A Gentle Introduction to the Web’s Most Popular Language, O’Reilly Media; 1st edition.