# PHP

## Contents

PHP is an open source, server-side, HTML embedded scripting language used to create dynamic Web pages. The advantages of PHP are its flexibility and its high compatibility with other databases. Moreover, PHP is considered to be easy to learn.

## Functions of PHP

The functions of PHP concern server-side scripts. PHP can perform any task that any CGI (Common Gateway Interface) program can do and handles data exchange between the server and software. Thus, PHP can collect data or create dynamic content websites.

Three main functions distinguish PHP in particular:

• Server-Side Programming: this requires three components. These are a PHP parser, a web browser and a web server. The latter is connected with a PHP installation. The web browser is used to access the PHP program. The browser displays webpages that are stored on the server and generated with PHP. Server-side programming is ideal for test sites prior to their publication on the web.
• Programming via the command line: PHP scripts can be created without a browser or server. In this case, you will only need a PHP parser. These scripts are suitable for regular tasks to be carried out on a website.
• Writing desktop applications: this function is not used as frequently as website programming. However, PHP is quite suitable for developing desktop applications due to its complexity, which can also be used across multiple platforms.

Example of an embedded PHP script in an HTML document:

 <!DOCTYPE HTML PUBLIC "-//W3C/DTD HTML 4.01 Transitional//EN
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Page with PHP script </title>
</head>
<body>
<?php
echo "This is a PHP script";
?>
</body>
</html>


## Benefits of PHP

The PHP scripting language can be used with all popular operating systems. Moreover, PHP is compatible with most web servers such as Apache. The user advantages at a glance:

• PHP can be used on virtually any operating system and any type of server
• The applications can be programed procedure-oriented or project-oriented
• HTML, images, PDFs, or flash files can be dynamically generated with PHP
• PHP supports a large amount of different databases which is why this scripting language is ideally suited for the creation of database-driven websites
• PHP offers comprehensive support for server communication with other protocols

A small disadvantage when programming with PHP is that it generates URLs that are usually cryptic for users and provide fewer keywords for search engines. But with a simple mod_rewrite the PHP-generated URLs can be converted to SEF URLs (Search Engine Friendly URLs).

Out

www.samplewebsite.com/index.php?id=fotos&foto=12456


becomes, for example

www. samplewebsite.com /vacation-at-the-Grand-Canyon.html


## Benefits for SEO

PHP allows webmasters to deliver content without placing it directly in the source code since the content is parsed by a PHP script. Unlike JavaScript, the code is executed on the server and then delivered to the client. That way content can be deliberately hidden from crawlers. Consequently, contest forms or surveys on customer satisfaction can be displayed without impairing or lessening the content and its optimization in any way.

Basically it is also possible to parse all HTML elements via PHP. In that case the original data would be completely obscured. This method would only be beneficial if content is not to be used for indexing.