PHP is a system

PHP is a system that handles the server side PHP-Code. This means that the source code is not sent to the web browser, but to an interpreter on the Web server. Only the output of the PHP interpreter is sent to the browser. In most cases, this is an HTML document, using PHP but it is also possible to generate other types of files, such as images or PDF files.

To run a PHP file in a web application, you need a system that can deal with the instructions contained in the file. For this reason, through an interface, such as ISAPI or CGI, the interpreter of a server daemon or server service such as Apache or IIS, run. The combination of Linux / Windows / OS X operating system, Apache Web server, MySQL database and PHP system is called LAMP (for Linux), WAMP (Windows) or MySQL (for OS X). Ready LAMP, WAMP, and MAMP packages that make the individual loading and configuring packages from the Internet unnecessarily will be developed in the project about XAMPP. There are versions for Linux, Solaris, Windows and Mac OS X.

Because PHP normally runs in a web server environment, it is also subject to stateless HTTP. Each PHP page loads the web server through the interpreter; the interpreter also operates the source code for each call from again. This reduces the response speed of the server, and increases the load. To counter this, various bytecode cache available to cache a prepared version of the implementation of the program and thus accelerate access to this file the next time.

With PHP can be written also command-line oriented scripts which are independent from the Internet. The Qt extension and the GTK extension even provide a programming interface for a graphical interface, for which neither the server nor a browser needed. The first versions of the graphical interface, and interfaces to other operating system functions were sparse and were hardly used. The currently developed PHP-GTK version 2 aims, however, a cover of the GTK API of 95% an.Gegenwärtig PHP is used but mainly web servers.

Thank you. Sven