PHP's require () performance is similar to include (). The difference is that, for the include (), the file is read and evaluated every time the include () is executed, and for require (), the file is processed only once (in fact, the file contents replace the Require () statement). This means that if you have code that contains one of these directives and code that might execute multiple times, using require () is a high efficiency. On the other hand, if you read a different file each time you execute the code, or you have a loop that iterates through a set of files, you use include () because you can set a variable for the file name you want to include, and use that variable when the parameter is include ().
Original Author: unknown
Source: MySQL Guide
The above describes the inclusion () and require () in PHP, including the content of the include,require aspects, I hope that the PHP tutorial interested in a friend helpful.
