Introduction to PHP
PHP (acronym for Hypertext Preprocessor) is an open-source server-side scripting language that is used to develop dynamic and interactive web applications and also used as a programming language. PHP is an interpreted programming language whose implementations execute instructions directly and freely, without previously compiling a program into machine-language instructions.
PHP is a platform independent language and PHP code can be embedded into HTML tags and script. A PHP file contains PHP tags and ends with the extension ".php". The server interprets the PHP code and outputs the results as HTML code to the web browsers. In order for the server to identify the PHP code from the HTML code, we must always enclose the PHP code in PHP tags.
<?php ….. ?>
It is integrated with a number of popular databases, including MySQL, PostgreSQL, Oracle, Sybase, Informix, and Microsoft SQL Server. PHP supports a large number of major protocols such as POP3, IMAP, and LDAP. PHP4 added support for Java and distributed object architectures (COM and CORBA), making n-tier development a possibility for the first time.
PHP is one of the most widely used server side scripting language for web development. Popular websites like Facebook, Yahoo, Wikipedia etc are developed using PHP.