In this example, the `ini_set()` function is used to set the `display_errors` and `memory_limit` variables. The first directive enables PHP error reporting, and the second directive sets the memory limit to 256MB. Package library: The PHP app conf is part of the PHP core package, which includes all the necessary libraries and modules for running PHP scripts. There are also third-party packages available that provide additional functionality for PHP applications, such as the Symfony and Laravel frameworks.