The PHP language has a core and language extensions. It is rather difficult to draw a boundary between the kernel and extensions, since many extensions have long been included in the kernel or distributed as compiled binary libraries and are easily installed.
There is another part – the code created in PHP, which can be divided into the following types:
- components are PHP libraries that are built using the Composer package manager (see Chapter 26);
- frameworks – ready-made assemblies, often from components with which you can create sites of any degree of complexity. In the book, unfortunately, we don’t touch them, however, if you choose PHP as the main development language, you won’t pass them by. The following PHP frameworks should be noted: Symfony, Laravel, Zend, Yii. There are hundreds, if not thousands;
- ready applications – ready-to-use development on PHP. These are content management systems (WordPress, Drupal), forums (phpBB), Web-based database management interfaces (phpMyAdmin, pgAdmin).
The book you hold in your hands will introduce you to the language; The systems described above are created using the PHP language, but they require separate study and, unfortunately, their discussion is beyond the scope of our book.