Plugins, are the special software codes, which help your favorite Mozilla Firefox browser to perform specific functions like viewing special graphic formats or playing multimedia files. Plugins are slightly different from extensions, whose primary task is to modify or add to existing functionality.
Whenever you visit a web page, which has an element, which requires you to download a firefox plugin, Firefox give you a message, and prompts you to permit downloading it. On download, it gets automatically installed and you can see that element.
Alternatively, if you want to avoid such hassles, and equip your Firefox with the most useful plugins beforehand, you can download and install these most common plugins.
Most Common Firefox Plugins
Adobe Flash Player
Adobe Flash Player is the universal rich client for delivering effective Adobe Flash experiences across desktops and devices.
By Adobe | | Review