Data structures and algorithms are an integral part of software application development. Whether we are building a web-based application, a CMS, or a standalone backend system using PHP, we need to apply algorithms and data structures all the time. Sometimes, we do that without noticing and sometimes without giving proper attention to it. Most developers think that these two topics are really difficult and there is no point in paying attention to details as PHP has lots of built-in support for data structures and algorithms. In this book, we will focus on the basics and practical examples of PHP data structures and algorithms so that we know what data structures are, why to choose them, and where to apply which algorithms. This book is designed for novice as well as experienced PHP programmers. The book starts from basic topics and moves on to more advanced topics. We have tried to accommodate lots of examples with images and explanations in this book so that you can understand the concepts properly in visual form and with practical examples.