The purpose of a plug-in, is to extend the functionality of the HTML browser.
HTML Helpers (Plug-ins)
Helper applications are known to be computer programs which is used for extending a web browser's standard functionality.
Helper applications are known with another name called plug-ins.
One of the well-known plug-ins are Java applets.
Plug-ins are added to the web pages using the <object> tag or the <embed> tag.
Plug-ins are used for many functions: display maps, scan for viruses, verify your bank id, etc.
For displaying video and audio: Utilise the <video> and <audio> tags.
The <object> Element
All browsers will support the <object> element.
The <object> element is used to define an embedded object inside an HTML document.
It is utilised for embedding plug-ins (like Java applets, PDF readers, Flash Players) in various web pages.
The <object> element is also used for including HTML in HTML:
Or images if needed:
The <embed> Element
The <embed> element is supported by most of the browsers.
The <embed> element is also used to define an embedded object inside an HTML document.
Web browsers are supporting the <embed> element for a long time. But, it has not become a HTML specification's part before HTML5. The element will get validated in an HTML5 page, but does not get validated in an HTML 4 page.
Note that the <embed> element is not having a closing tag. It does not have alternative text.
The <embed> element are also be used for including HTML in HTML:
Or images if needed: