To explore the code of defualt featured module, let's start with listing what files are used by the Featured module:
Admin folder files:
admincontrollerextensionmodulefeatured.phpExplained at https://webocreation.com/exploring-the-code-of-default-featured-module/adminlanguageen-gbextensionmodulefeatured.phpExplained at https://webocreation.com/exploring-the-code-of-default-featured-module/adminviewtemplateextensionmodulefeatured.tplExplained...