Arrays are considered one of the most useful features in PHP. An array allows you to store multiple values in one variable. Arrays are indexed numerically, similar to an associative array in Perl. However, unlike Perl, you cannot assign values to these indexes. Arrays in PHP are just collections of variables that you can access with one variable name. By default, PHP arrays are ordered. This means that you can access specific elements using the array name and the element's index (position) in the array.