Active Server Pages: "Server-Side Includes"
Server-side includes are a technique for including the contents of another file in an HTML file. This is an advanced technique that requires further instruction; the purpose of this short reading is to familiarize you with a common use-case so that you are ready to seek help of a skilled programmer or so that you know one of the directions you can continue your study of core Internet technologies.
Click https://en.wikibooks.org/wiki/Active_Server_Pages/Server-Side_Includes link to open resource.