The <object> tag is used to include objects such as images, audio, videos, Java applets, ActiveX, PDF, and Flash.
The object element was intended to replace the img and applet elements. However, because of bugs and a lack of browser support this has not happened.
The object support in browsers depend on the object type. Unfortunately, the major browsers use different codes to load the same object type.
Luckily, the object element provides a solution. If the object element is not displayed, the code between the <object> and </object> tags will be executed. This way we can have several nested object elements (one for each browser).