Server Side Includes (SSI) is a well-known server-side scripting language, used to incorporate the content of one file inside of another file. It is employed principally with online content and it could help to make a static HTML website far more dynamic. If you'd like to have a daily quote shown on a variety of pages on your site, for instance, you can create a text file and switch the quote inside it every day. All the pages where this file is incorporated will show the modified quote, so you'll not have to modify them by hand each time. SSI may also be used to include the output of simple functions rather than a static file - for example, the client's IP address, a hit counter or even the current time and date. By doing this, you may make your website look much more professional and more attractive to the visitors. Web pages that use SSI use a .shtml extension.