PHP is a widely-used open source general-purpose scripting language that is especially suited for web development and can be embedded into HTML.
History of PHP
PHP created by Rasmus Lerdorf in 1994.
It started as a collection of UNIX specific HTTP server modules.
Common Gateway Interface (CGI) are written in C Language.
PHP modules managed by PHP Parser.
What is PHP?
PHP is a widely-used, open source scripting language.
PHP is free to download.
It is a recursive acronym for “PHP: Hypertext Preprocessor”.
PHP code is embedded within HTML pages.
Enclosed within the special start and end tags
<?php and ?>
The processing of PHP
When you use a browser to display a web page on your computer, the remote web server reads the PHP and processes it according to the code. The PHP processor then sends the generated HTML to your web browser.
So PHP creates an HTML page on the fly based on the coding that you have created in the PHP page.
According to above image client is your local computer, while the Server is the remote computer which will be a web server.
Design goals of PHP
Web was first priority
1) Easy access to HTTP variables
2) Build in support for sessions and cookies
1) Support for many database
2) Command-line scripting
3) It can be embedded in XML
Some Characteristics of PHP
1) PHP can interact with many different database languages including MySQL.
2) PHP and MySQL are compatible with an Apache server.
3) It have ability to develop client side application for any platform.
4) PHP is a free and open source platform.
PHP Application In The World
Around 20 million or more Websites including:
WordPress: It is the biggest blogging system on the web.
Facebook: It is the largest social network.
Yahoo: It is a web service provider.