Include page usually used when you want to duplicate part of a page in more than one page
such as the header and footer of the site
There are two functions to include PHP page to another page.
<!doctype html> <html> <head> <title>Hello, world!</title> </head>
<?php include("header.php"); ?> <body> </body> </html>
now run the index.php and look to the source code from the browser
you can see
The same of require() Function, but the difference between include() and require() is, If the include() can`t load the page the script will continue and emit a warning but require() will emit a fatal error and stop the script.