Browser extensions are programs that can be installed on your browser in order to augment the browser’s functionality. This includes adding new features to your browser or modifying the existing behavior of the program itself to make it more convenient for the user. Extensions offer a wide range of additional functionality so that you can perform tasks easier or get more out of the websites you visit. But not all extensions are helpful, some developers create extensions that modify the behavior of the browser in a negative way. For example, adware developers may install browser extensions without your permission that inject advertisements onto web pages that you are viewing, change your search provider to a site under their control, change the new tab page, or hijack your home page. A browser extension is a small software module for customizing a web browser. Browsers typically allow a variety of extensions, including user interface modifications, ad blocking, and cookie management. Browser plug-ins are a separate type of module. The main difference is that extensions are usually just source code, but plug-ins are always executables. As of 2021, plug-ins have been deprecated by most browsers, while extensions are widely used. The most popular browser, Google Chrome, has thousands of extensions available but only one plug-in, the Adobe Flash Player, that is disabled by default.