SSI server side includes

Server side includes are variables that come from the server. You should rename your html pages to shtml if you use SSI.

What if I don't want to use .shtml?

Some common SSI codes:
<!--#echo var="HTTP_REFERER" -->(referring URL)
<!--#echo var="REMOTE_ADDR" -->(visitor's IP address)
<!--#echo var="REQUEST_URI" -->(requested URL)
<!--#echo var="HTTP_HOST" -->(server name)
<!--#echo var="HTTP_USER_AGENT" -->(visitor's browser)
<!--#echo var="REDIRECT_STATUS" -->(redirect status code)
<!--#echo var="DATE_LOCAL" -->(visitor's date and time)
<!--#include virtual="path/file.ext" -->(file include)