Module

In computer science, a module refers to a self-contained unit of code or software that encapsulates a specific functionality or set of related functionalities. It is a fundamental concept in modular programming, which aims to break down complex systems into smaller, more manageable components.

In the PHP world, modules often refers to specific frameworks’ component : for example, Drupal and Laravel use modules to extends their features.

See also https://www.drupal.org/project/project_module

Related : Plugin, Extensions