I think of a web server as a service that wraps around the data stored on the hard drive, very much like a waiter might take your order and come back with your refreshments.

If I were to place an order for a rack of ribs, it wouldn't very likely be a waiter cooking those ribs for me. Neither would it be very likely that a web server would generate my dynamic content.

The best a web server could do on its own without a scripting engine would be to pick up a pre-made salad from the cooler and plop it on your table. Without Javascript in those web pages, it couldn't even set your utensils for you.

There may be some exceptions with new web development packages like Ruby on Rails springing up all about, but most scripting languages for the web like PHP, Asp, and ColdFusion are not web servers. They are scripting languages that are executed by a scripting engine.

The scripting engine is like the cook in the restaurant. The database that it might connect to in order to retrieve such information as your account information, your favorite movies, or your blogs could be like the refrigerator and the oven - with the scripting engine gathering your content and preparing it before handing it over to the waiter (the web server), for delivery.

Web servers are always waiting.

"May I take your order, sir?" is a standing request. Every website in the world is waiting for my order.

"I'll have the baked scrod with the garlic mashed, please," I might say as I click on the link for automobiles.

"And would you like corn or broccoli with that?" the web server sends back a request to my browser asking if there is a cookie it might use with my stored settings for vegetables.

"Neither, thanks. I don't approve of what you folks do with the vegetables" as I've chosen not to store my preferences by disabling cookies on my computer.

The web server then checks the order for the automobiles and finds that the extension of the page matches what should be executed by the scripting engine. For example, if the page ends in a .php extension (and it's been configured correctly), the web server should pass off execution to the php engine before serving the content back to my computer.

It turns out my fish is going to take some work by the scripting engine.

The web server takes the order back to the scripting engine since it cannot process a baked scrod. The scripting engine then calls the shots as it reads the order with the dynamic page.

"One crusty fish for a paranoid vampire!"

The cook rushes to the refrigerator where all the data is stored fresh from the market today and prepares it as the scripting in the page dictates.

The scripting engines creates a fine meal, and packages it on the plate as the page has specified and the customer tweaked.

"Order's up!" and back rushes the waiter to serve your meal.

If you're still on dial-up, this may be the time you're kicking yourself for not opting for fast food.

Learn more about this author, Patrick Vincent.
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