The PHP array is one of the most used data types in PHP. Most of the time we use it without considering the impact of PHP arrays in our developed code or application. It is so easy to use and dynamic in nature; we love to use PHP arrays for almost any purpose. Sometimes we do not even want to explore if there are other available solutions which can be used instead of PHP array. In this chapter, we are going to explore the positives and negatives of PHP arrays, along with how to use arrays in different data structure implementations along with boosting performances. We will start with explaining different types of arrays in PHP followed by creating fixed sized arrays. Then we are going to see the memory footprints for PHP array elements and how can we improve them along with some data structure implementations.