require() and include()

require() and include() are identical in every way except how they handle failure.
include() produces a Warning while require() results in a Fatal Error.
In other words, don’t hesitate to use require() if you want a missing file to
 halt processing of the page. include() does not behave this way,
the script will continue regardless. Be sure to have an appropriate
include_path setting as well.

* require() : If the file does not exist, you will get a fatal error.

* include() : If the file does not exist, you will get a warning and the next line of code will execute.