Wicked Cool PHP

Chapter 8. USER AND SESSION TRACKING

The World Wide Web's initial design was little more than a series of static pages and media. The design made it easy to publish and navigate pages, but the Web truly became useful when sites began to offer dynamic content. Much of this content is specific to a session —a shopping cart, for instance, is session data; it is generally unique to one browser (or user).

The tools and techniques for tracking web sessions are afterthoughts and hacks —ones that happen to do a somewhat reasonable job. Sometimes things get messed up, and you must be careful about security (as ever), but PHP can remove some of the complexity ...