What is PHP Web Development?
PHP is an open-source server-side scripting language designed for Web development to produce dynamic Web pages. It is one of the first developed server-side scripting languages to be embedded into an HTML source document rather than calling an external file to process data. The code is interpreted by a Web server with a PHP processor module which generates the resulting Web page. It has also evolved to include a command-line interface capability and can be used in standalone graphical applications. PHP can be deployed on most Web servers and also as a standalone shell on almost every operating system and platform, free of charge.( Courtsey Wikipedia)
PHP was originally created by Rasmus Lerdorf in 1995. The main implementation of PHP is now produced by The PHP Group and serves as the formal reference to the PHP language.PHP is free software released under the PHP License, which is incompatible with the GNU General Public License (GPL) due to restrictions on the usage of the term PHP.
Of course, the question is why PHP web development has become so popular.
The answer is in how it works. With PHP web development, those servers contain a script that responds to data from the web site in order to generate new web pages. Popular sites, such as Wikipedia, are written in PHP.