PHP with Framework is termed as PHP and core-PHP/plain PHP is termed as PHP-RAW. ... Like wordpress; they have every code handwritten and it follows both RAW and Framework based approach. They have written own ORM to facilitate easy Data CRUD though their database is fixed to MySQL.
How php works
The PHP software works with the web server, which is the software that delivers web pages to the world. When you type a URL into your web browser’s address bar, you’re sending a message to the web server at that URL, asking it to send you an HTML file. The web server responds by sending the requested file. Your browser reads the HTML file and displays the web page.
You also request a file from the web server when you click a link in a web page. In addition, the web server processes a file when you click a web page button that submits a form. This process is essentially the same when PHP is installed. You request a file, the web server happens to be running PHP, and it sends HTML back to the browser, thanks to the programming in PHP.
More specifically, when PHP is installed, the web server is configured to expect certain file extensions to contain PHP language statements. Often the extension is .php or .phtml, but any extension can be used. When the web server gets a request for a file with the designated extension, it sends the HTML statements as is, but PHP statements are processed by the PHP software before they’re sent to the requester.
When PHP language statements are processed, only the output, or anything printed to the screen is sent by the web server to the web browser. The PHP language statements, those that don’t produce any output to the screen, aren’t included in the output sent to the browser, so the PHP code is not normally seen by the user.