Web Application Development with PHP 4.0

Chapter 4. Web Application Concepts

                        We join spokes together in a wheel,        but it is the center hole that makes the wagon move.                                   We shape clay into a pot, but it is the emptiness inside that holds whatever we want.                                 We hammer wood for a house,            but it is the inner space that makes it livable.

To understand the implications of Web application concepts, you need to differentiate between applications and single scripts. A script is a utility, and as such doesn't have any context. It doesn't know about other scripts in your system. An application, however, is designed to perform more advanced tasks. An application needs to maintain state and execute ...