Server Side Includes (SSI) is a well-known server-side scripting language, used to add the content of one file inside of another file. It is utilized mainly with online content and it will make a static HTML site a lot more dynamic. If you need to have a daily quote displayed on many pages on your site, as an example, you can make a text file and replace the quote in it every day. All pages where this file is incorporated are going to display the modified quote, so you will not have to update all of them manually every single time. SSI could also be used to contain the output of basic functions instead of a static file - for example, the client's IP address, a hit counter or even the current date and time. By doing this, you may make your site seem much more professional and a lot more appealing to the website visitors. Pages that employ SSI use a .shtml extension.