Server Side Includes

Example of SSI

<!--#include file="includes/inc_header.html"-->

SHTML

A Web file with the suffix of .shtml, .stm, or .shtm (rather than the usual .htm) indicates that there will be server side information added on the fly to the file.

Common uses for this: to include a "Last modified" date at the bottom of the page, or for including headers/footers.