PHP Primer Two "PHP include and require differences"

The include (or require) statement gets all the text/code/tags that exist in the specified file and is copied to the file that uses the include statement.
The include file is useful if you need to refer to the same PHP, HTML, or text on multiple pages of the site.

With the include or require statement, you can insert the contents of a php file into another PHP file (before the server executes it).
The Include and require statements are the same, in addition to error handling:

• Require generates a fatal error (E_COMPILE_ERROR) and stops the script
• Include only generates a warning (e_warning), and the script continues

Instance:

PHP include ' nofileexists.php '; Echo $color $car. " ;? ></body>
PHP require ' nofileexists.php '; Echo $color $car. " ;? ></body>
Therefore, if you want to continue execution and output the results to the user, use include if the included file is missing. Otherwise, in framework, CMS, or complex PHP application programming, always use require to reference critical files to the execution stream. This helps improve the security and integrity of your application in the event that a critical file is accidentally lost.
The inclusion of files saves a lot of work. This means that you can create a standard header, footer, or menu file for all pages. Then, when the page header needs to be updated, you only need to update the header include file.
Comments:
Please use require at this time: when the file is requested by the application.
Use include at this point: when the file is not required, and the application should continue to run when the file is not found.
PHP Primer Two "PHP include and require differences"