Reading this book will enable you to build real-world, dynamic web applications. If you’ve built websites using plain HTML, you realize the limitations of this approach. Static content from a pure HTML website is just that—static. It stays the same unless you physically update it. Your users can’t interact with the site in any meaningful fashion.Using a language such as PHP and a database such as MySQL allows you to make your sites dynamic: to have them be customizable and contain real-time information.We have deliberately focused this book on real-world applications, even in the introductory chapters. We begin by looking at simple systems and work our way through the various parts of PHP and MySQL.We then discuss aspects of security and authentication as they relate to building a real-world website and show you how to implement these aspects in PHP and MySQL. We also introduce you to integrating front-end and back-end technologies by discussing JavaScript and the role it can play in your application development.