Server Side Includes (SSI) is a basic server-side language, which lets you incorporate text from a specific source within a website. In the most popular situation, the text from a file is integrated in a different one, giving a site the sense it is dynamic. As an example, if your website features 10 webpages, 5 of them can easily include the content of any kind of file, for example horoscope.txt. If you alter this text file, the updated content will appear on all of the five pages, which shall enable you to bring up to date your website much easier than if you had to change part of all 5 pages. Server Side Includes is at times utilized to include the output of simple commands, scripts or functions as well - a hit counter that's displayed on the website, the present time and date or the visitor's IP address. Any webpage that works by using SSI should have a special extension - .shtml.