Server Side Includes (SSI) is a group of directives that will enable you to include the content of a text file within an HTML file. By doing this, you're able to add some content to various web pages on your website and adjust it just by editing a single text file. You're able to furthermore add the output of distinctive scripts so the present time and date, the IP address of the website visitor or the properties of some file appear on your site. This will enable you to add some dynamic content to static pages, making the website more inviting to your site visitors and giving it a much more professional appearance. It will likewise be much easier to update this content compared to editing each static web page one by one. If you would like to use Server Side Includes in your website, the web pages that contain the content of any kind of file must be with extension .shtml.