Personal Home Page (PHP)
Started as a personal web project by Rusmus Lerdorf in 1994. The original acronym PHP stood for Personal Home Page. At the time web programmers used either C or Perl. Finding Perl too slow, and C to cumbersome to create web pages, Lerdorf wanted to provide means to generate web pages easily by separating the web content (HTML, styles) from the programming code. He designed PHP as a scripting language specifically to generate dynamic web pages.
Scripting inside the web page
PHP permitted web developers to add to thier HTML web pages PHP scripting which was processed via the web server. Typically the PHP interpreter is integrated as a web server module. The PHP code generates new (or dynamic) web content to the web page which is then sent to the browser. Incidentally, the web page you are reading now was generated by PHP. Writing PHP was easier for web developers, some of whom had little or no exposure to programming.
A PHP scenario
A user enters their name and password onto the web page, then clicks on the Login button. Clicking the button actions a request sent across the internet to the web site. At the site, the web server handles all web traffic. It has PHP linked to it, so if the server finds any PHP scripting in the web page it calls the PHP module to process it. PHP makes a authenticated user request to the database (mySQL, SQL Server, Oracle etc). The database searches for the login name and associated password exist and match each other. PHP receives the response from the database, and either outputs the login page or sends the login page with a message to try again. Any web output from PHP is sent via the web server.
LAMP is an acronym for Linux, Apache, MySQL and PHP. All this software are open source products which work well together for web development. The combination is attractive as no license fees required to use open-source software. The 'P' in LAMP can sometimes stand for Perl or Python.
PHP is familiar to C and Perl programmers. PHP itself is written in C. PHP has good library support, with particular emphasis on web related functions (database, web services, ftp, email). PHP (now on version 5) has evolved over time, now has additional programming features such as object orientation, and improved performance.
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