PHP generally runs on a web server, taking PHP code as its input and creating Web pages as output, however you can also use it for command-line scripting and client-side GUI applications. PHP is an extremely versatile language which enables you to create high-end, stable Web sites with plenty of bells and whistles. Here are just a few of the things you can do with PHP:
Make HTML Web Forms
Store Information in Databases
Remember Web site visitors (cookies and sessions)
Work with Arrays
Work with Files (File Management and downloads)
Parsing and Generating XML (also useful for large quantities of products on e-commerce)
Check which browser your visitor is using
How does PHP Work?
As its name ("PHP: Hypertext Preprocessor") suggests, PHP derives its power by "preprocessing" hypertext on the server side. This generally means that when the PHP script (saved as a .php file) runs on your web server, it performs the programmed actions, and returns HTML code that will then be sent back to your customer's web browser. The PHP script itself is not included in the HTML that is sent to the browser, so the PHP code is invisible and secure to the user.
For example, let's consider the following simple PHP statement. (This example is merely to show the basic syntax of PHP in action. Any detailed discussion of PHP code is beyond the scope of this article.)
Hello World"; ?>
In this statement, is the closing tag, and echo is a PHP instruction that tells PHP to output the text that follows it as plain HTML code. The PHP software processes the PHP statement and outputs the following:
Hello World
This is a regular HTML statement that is delivered to the user’s browser. The PHP statement itself is not delivered to the browser, so the user never sees any PHP statements.
Using PHP to Improve Your Website.
PHP has many capabilities features designed specifically for use in Web sites, including the following:
1. Securing Your Website.
PHP can be used to secure your website (or certain areas of your website) so that your customer must enter a valid username and password. This can be used to reward preferred customers and to build an exclusive "membership" component of your business.
2. Working with Web Forms.
PHP can display an HTML form and process the information that the user types in. This can be an excellent way to learn more about your customers by asking them to provide profile information, and to collect information about their specific interests.
3. Communicate with Your Databases.
PHP is particularly adept at interacting with your databases, and storing information from the user or retrieving information that is displayed to the user. PHP handles connecting to the database and communicating with it, so it's not necessary to know all of the technical details for connecting to or exchanging messages with the database. You tell PHP the name of the database and where it is, and PHP handles the details. All major databases are currently supported by PHP.
4. Customer Loyalty Functions.
You can also use PHP to create a number of different functionalities on your website that will further help you to build customer loyalty, including interactive polls, a guestbook, and a message board.
The popularity of PHP continues to grow rapidly because it has many advantages over other technical solutions. PHP is fast (because it's embedded in the HTML code, the time to process and load a Web page is relatively short), PHP is free (it is open-source software), and PHP is versatile (is runs on a wide variety of operating systems, including Windows, Mac OS, Linux, and most Unix variants).
Perhaps most importantly, PHP is a very well-established language. There are many user-run Internet communities that make very large amounts of information (and scripts) available. With so much experience behind it, using PHP for certain dynamic features can be a cost-effective and low-hassle way of increasing the stability of your website.
