// URL: http://example.com/search.php?q=example $q = $_GET['q']; echo "You searched for: " . $q;This example shows how to retrieve data input from a query string using the $_GET variable. The user enters their search term in the URL query string, and the application retrieves it in search.php and echoes the search term. Package library: PHP Request input is part of the core PHP language and does not require any external package library. However, there are various PHP frameworks and libraries that offer additional features and functionality for handling input data and validating user input, such as Laravel, Symphony, and CodeIgniter.