PHP Programing | PHP Basic | chapter 1 Introduction and installing PHP

In this article and the other artile that related to this article a I will discused about PHP programing, I take some of the article from PHP manual that can be redistributed under the terms of the GNU General Public License as published by the Free Software Foundation writen by Stig Sæther Bakken, Alexander Aulbach, Egon Schmid, JimWinstead, Lars Torben Wilson, Rasmus Lerdorf, Zeev Suraski, Andrei Zmievski,Jouni Ahto.thanks a lot to them. Besides the PHP manual above I use the reference from a book “Pemrograman Web Dengan PHP” writen by Betha Sidik, Ir. The book is in the Indonesian language so I translate some oh it into english. Im apologize if the english is teribble because I still learn english and always learning. Thx

Introduction
PHP was conceived sometime in the fall of 1994 by Rasmus Lerdorf. Early non-released versions were used on his home page to keep track of who was looking at his online resume. The first version used by others was available sometime in early 1995 and was known as the Personal Home Page Tools. It consisted of a very simplistic parser engine that only understood a few special macros and a number of utilities that were in common use on home pages back then. A guestbook, a counter and some other stuff. The parser was rewritten in mid-1995 and named PHP/FI Version 2. The FI came from another package Rasmus had written which interpreted html form data. He combined the Personal Home Page tools scripts with the Form Interpreter and added mSQL support and PHP/FI was born. PHP/FI grew at an amazing pace and people started contributing code to it.
It is difficult to give any hard statistics, but it is estimated that by late 1996 PHP/FI was in use on at least 15,000 web sites around the world. By mid-1997 this number had grown to over 50,000. Mid-1997 also saw a change in the development of PHP. It changed from being Rasmus' own pet project that a handful of people had contributed to, to being a much more organized team effort. The parser was rewritten from scratch by Zeev Suraski and Andi Gutmans and this new parser formed the basis for PHP Version 3. A lot of the utility code from PHP/FI was ported over to PHP 3 and a lot of it was completely rewritten. The latest version (PHP 4) uses the Zend scripting engine to deliver higher performance, supports an even wider array of third-party libraries and extensions, and runs as a native server module with all of the popular web servers.
PHP 4 now ships with a number of commercial products such as Red Hat's Stronghold web server. A conservative estimate based on an extrapolation from numbers provided by Netcraft (see also Netcraft Web Server Survey) would be that PHP is in use on over 5,100,000 sites around the world. To put that in perspective, that is slightly more sites than run Microsoft's IIS server on the Internet (5.03 million).
PHP (officially "PHP: Hypertext Preprocessor") is a server-side HTML-embedded scripting language. Simple answer, but what does that mean? An exampblogger

Notice how this is different from a CGI script written in other languages like Perl or C -- instead of writing a program with lots of commands to output HTML, you write an HTML script with a some embedded code to do something (in this case, output some text). The PHP code is enclosed in special start and end tags that allow you to jump into and out of PHP mode.

What distinguishes PHP from something like client-side Javascript is that the code is executed on the server. If you were to have a script similar to the above on your server, the client would receive the results of running that script, with no way of determining what the underlying code may be. You can even configure your web server to process all your HTML files with PHP, and then there's really no way that users can tell what you have up your sleeve. At the most basic level, PHP can do anything any other CGI program can do, such as collect form data, generate dynamic page content, or send and receive cookies.
Perhaps the strongest and most significant feature in PHP is its support for a wide range of databases. Writing a database-enabled web page is incredibly simple. The following databases are currently supported:

Adabas D Ingres Oracle (OCI7 and OCI8)
dBase InterBase Ovrimos
Empress FrontBase PostgreSQL
FilePro (read-only) mSQL Solid
Hyperwave Direct MS-SQL Sybase
IBM DB2 MySQL Velocis
Informix ODBC Unix dbm
PHP also has support for talking to other services using protocols such as IMAP, SNMP, NNTP, POP3, HTTP and countless others. You can also open raw network sockets and interact using other protocols.

PHP Instalation
The source code, and binary distributions for some platforms (including Windows), can be found at http://www.php.net/. We recommend you to choose mirror nearest to you for downloading the distributions.
The Windows PHP installer available from the downloads page at http://www.php.net/, this installs the CGI version of PHP and, for IIS, PWS, and Xitami, configures the web server as well.
Install your selected HTTP server on your system and make sure that it works.
Run the executable installer and follow the instructions provided by the installation wizard. Two types of installation are supported - standard, which provides sensible defaults for all the settings it can, and advanced, which asks questions as it goes along.
The installation wizard gathers enough information to set up the php.ini file and configure the web server to use PHP. For IIS and also PWS on NT Workstation, a list of all the nodes on the server with script map settings is displayed, and you can choose those nodes to which you wish to add the PHP script mappings.
Once the installation has completed the installer will inform you if you need to restart your system, restart the server, or just start using PHP.
After Complete instal the PHP and the webserver we can start using php in the computer.