CHAPTER 1Introducing PHP
In many ways the PHP language is representative of the stereotypical open source project, created to meet a developer's otherwise unmet needs and refined over time to meet the needs of its growing community. As a budding PHP developer, it's important you possess some insight into how the language has progressed, as it will help you to understand the language's strengths, and to some extent the reasoning behind its occasional idiosyncrasies.
Additionally, because the language is so popular, having some understanding of the differences between the versions—most notably versions 4, 5, and 6—will help when evaluating Web hosting providers and PHP-driven applications for your own needs.
To help you quickly get up to speed ...