For considerable performance gains, there are several changes that you can make to your application as well as your web server environment that can significantly increase the performance of your application.
Unlike compiled languages such as C and C++, PHP is an interpreted scripting language. Consequently, every time our web server requests a new page or every time we run a command from our command line, PHP needs to interpret our code into machine code that our servers can actually run. Even if our source code doesn't change, PHP will automatically perform this step on every request. In our development environments, this allows us to simply make a change to our source code, save the file, and then reload it in the page to see our changes. In a production environment, however, this step is unnecessary since our code will only change if we perform a deployment.
Starting in PHP 5.5, a new tool called OPCache was released by Zend Framework Technologies...