<p>A plugin is a piece of software that acts as an add-on to a web browser and gives the browser additional functionality. Plugins can allow a web browser to display additional content it was not originally designed to display.</p><p style="text-align: start">An example of a plugin is the free Macromedia Flash Player, a plugin that allows the web browser to display animations using the Flash format. As the Web has become more commercial, Flash has become a popular format for displaying ads in web pages. As a result, many web users have been prompted to download the Flash plug in and have it installed on their systems.</p>