The short answer is: every class you create in Angular is a module. The contents of a module could be anything. It could be a component, a service, a simple piece of data, and even they could be a library of other modules. They might look different, but they share one purpose: modules bring (export) one piece of functionality to the Angular projects.
Note
Creating Angular projects in a modular fashion makes the testing and maintenance tasks easy and helps the scalability in the future. However, you are not limited to an Angular modular approach and you can use your own style.
Later in this chapter, we will see that there is an export keyword in front of each class keyword:
export class MyClassName{}
This is how Angular shares the logic inside that module (class) with the rest of the project. To use this module in other parts of a project, we just need to import it. Imagine the preceding code is saved inside a file named: myclassname.ts. To use that module in another module...