All the applications must be modularized so that they become easy to maintain and develop. In Rust, we can have a powerful module system for our application that could hierarchically split the application source code into logical units, which we call modules, and manage their visibility (public/private) across the application.

The dictionary description of a module is that it's a collection of items, such as functions, structs, traits, impl blocks, and even other modules.

You will learn how to create a sample module and understand the concept of visibility in this recipe.