What is a module?

In Angular 7, a module is a mechanism for organizing an application into cohesive blocks of functionality. It’s a container for a set of components, directives, pipes, and services, which are related to each other. Modules help in managing the complexity of large applications by breaking them down into smaller, manageable chunks.

Here’s a more detailed breakdown:

1. NgModule Decorator: In Angular, modules are defined using the NgModule decorator, which takes a metadata object where you specify various aspects of the module such as imports, declarations, providers, and exports.
2. Organization: Modules help in organizing an Angular application into logical units. These units can represent features, reusable components, or services.
3. Encapsulation: Modules encapsulate related functionality and provide clear boundaries within an application. This helps in separating concerns and maintaining a clean architecture.
4. Reusability: Modules can be reused across different parts of the application or even in other applications. This promotes code reusability and maintainability.
5. Lazy Loading: Angular allows for lazy loading modules, which means that modules are loaded only when they are needed. This helps in optimizing application loading times, especially for large applications.
6. Dependency Injection: Modules in Angular play a crucial role in dependency injection. Providers specified in a module’s metadata are available throughout the module and its components, allowing for the injection of dependencies wherever needed.

In summary, a module in Angular 7 is a logical unit of organization for an application, encapsulating related functionality, promoting reusability, and facilitating dependency injection.