PHP is a popular general-purpose scripting language that is especially suited to web and app development working in real time. PHP is flexible and fast and can be used to create a blog to the most popular websites in the world.
PHP is used to create scripts executed on the server side, but it can be also used to process data from the command line and run apps in graphical interface mode. To do it you need to use a special library. PHP allows you to work with few sources data like text files, XML documents, WWW platforms or database management systems. PHP is a module based language that makes it possible to write standalone apps with graphical user interface.
Scripts created in PHP language are usually stored in text files, sometimes also mixed with HTML and XHTML code. PHP can be also executed from the command line like Perl, Python and Ruby scripts.