The DWS WP Framework has a modular design and thus consists of multiple so-called modules. Currently, there's 7 different modules that more-or-less build on top of each other. In relative order, they are:
- 1.Bootstrapper Module -- validates that appropriate versions of PHP and WordPress are running or displays a user-friendly error if not.
- 2.Helpers Module -- a collection of small, helpful, static snippets that can be reused across various projects.
- 3.Foundations Module -- a collection of abstractions useful for building semantically-rich plugins; technically, simple plugins can already be built at this level.
- 4.Utilities Module -- a collection of services for working with template files, value validation, admin notices, dependencies, hooks etc.
- 5.Core Module -- an opinionated collection of abstractions for building plugins; relies on the abstractions defined by the Foundations Module and some services from the Utilities Module but its usage is optional.
- 6.Settings Module -- provides a unified way for interacting with various settings APIs like ACF, MetaBox, and WordPress itself.
The reasoning is simple. If you're building a plugin that's meant to be an extension for WooCommerce, then you probably want to include the WooCommerce module. If not, why would you want that code in your plugin? Similarly, you might want a very simple plugin that doesn't require any settings, so no settings module either. And so on...