Server Side Includes (SSI) is a common server-side scripting language, which is used to add the content of one file inside of another file. It is utilized primarily with online content and it could make a static HTML website far more dynamic. If you want to have a daily quote shown on a variety of pages on your site, for example, you can make a text file and replace the quote in it each day. All the web pages where this file is integrated are going to show the updated quote, so you will not have to update them personally every single time. SSI can also be used to include the output of simple functions instead of a static file - for instance, the viewer's IP address, a hit counter or the present date and time. In this manner, you can make your internet site appear much more professional and a lot more appealing to the website visitors. Web pages that implement SSI have a .shtml extension.