Server Side Includes (SSI) is a popular server-side scripting language, which is used to incorporate the content of one file inside another file. It's employed predominantly with online content and it will help make a static HTML website far more dynamic. If you want to have a daily quote shown on a variety of web pages of your website, for instance, you can make a text file and replace the quote inside it every single day. All pages in which this file is included are going to display the modified quote, so you will not have to alter all of them by hand every time. SSI can also be used to incorporate the output of simple functions instead of a static file - for example, the viewer's IP address, a hit counter or the current date and time. In this way, you may make your website seem much more professional and more attractive to the website visitors. Pages that implement SSI get a .shtml extension.