Server Side Includes (SSI) is a range of directives that will allow you to include the content of a text file within an HTML file. This way, you are able to add any kind of content to numerous webpages on your site and adjust it simply by editing just one text file. You can furthermore incorporate the output of different scripts in order that the current date and time, the IP address of the visitor or the attributes of some file appear on your website. This will help you add in some dynamic content to static webpages, making the site more desirable to your website visitors and giving it a much more professional appearance. It will be easier to update this content when compared with updating each static web page one by one. If you wish to use Server Side Includes on your website, the pages that include the content of some file need to be with extension .shtml.