PHP is a short form of Personal Home Page. It is a server side scripting language designed for creating dynamic web pages. PHP can be embedded into HTML source code and works as programming interface with the web server to provide dynamic content.
In its early days PHP scripts were written in HTML with some special PHP commands, however, since then the language has evolved to include not only filters to convert HTML to PHP but also filters to read as well as write XML and JSON. Its flexibility makes it an ideal language for those wishing to develop secure web applications. Additionally, PHP has become more important over years.