Curious how Angular apps are structured under the hood? Discover the essential building blocks — from components to services, routing to RxJS — with visuals and real examples. Whether you're a beginner or brushing up, this quick guide will give you a clear path through Angular’s architecture. Click to dive in!
Angular is more than just a front-end framework — it’s a powerful ecosystem built for scalability, modularity, and maintainability. Whether you’re building a small app or a large enterprise platform, understanding Angular’s architecture is essential.
In this blog, we’ll break down Angular’s architecture in a clear, visual, and beginner-friendly way — complete with code samples and a layered perspective.
Understanding how Angular’s layers work together is essential for writing maintainable code:
Presentation Layer (Components + Templates)
│
├── UI Logic (Forms, Events)
│
├── Service Layer (API Communication, Business Logic)
│
└── Data Layer (HTTP, Observables, State Management)
This structure helps:
At its heart, Angular uses a component-based architecture. Everything is organized around components and modules — allowing you to build feature-rich, testable applications.
Here’s a visual overview:
Angular Application
│
├── Modules (NgModules)
│ ├── Components
│ │ └── Templates + Styles + Logic (TypeScript)
│ ├── Services
│ │ └── Business Logic / API Communication
│ ├── Pipes
│ └── Directives
│
├── Routing
│ ├── RouterModule (Defines Routes)
│ └── <router-outlet> (Placeholder for Routed Views)
│
├── Dependency Injection System
│
└── RxJS (Reactive Programming with Observables)
Let’s break down each piece.
Modules are the organizational units of Angular. Every Angular app (up to version 16) has at least one module — the AppModule.
Note:-In the latest versions of Angular, Angular has by default standalone: true in a component, allowing us to import packages directly into the component without using modules.
They help you:
Separate features (e.g., using lazy loading for performance).
Boost reusability.
Here’s a basic example:
@NgModule({
declarations: [AppComponent],
imports: [BrowserModule],
bootstrap: [AppComponent]
})
export class AppModule {}
2. Components
Components are the heart of the UI.They are the building blocks of any Angular Applications. Each screen, button, form, or layout is typically a component.
A component includes:
@Component({
selector: ‘app-hero’,
templateUrl: ‘./hero.component.html’,
styleUrls: [‘./hero.component.scss’]
})
export class HeroComponent {
@Input() name: string;
}
Templates define how your UI looks. Angular’s powerful binding system connects your logic to the view:
[src]=”imageUrl” → Property Binding
(click)=”onClick()” → Event Binding
[(ngModel)]=”formValue” → Two-way Binding
This makes your UI reactive and dynamic.
Directives let you extend HTML with custom logic or behavior.
Angular has a built-in router to manage navigation between views.
Set up your routes like this:
const routes: Routes = [
{ path: ‘home’, component: HomeComponent },
{ path: ‘details/:id’, component: DetailsComponent }
];
In your main template (typically AppComponent), use <router-outlet> as a placeholder where routed components will be displayed:
<router-outlet></router-outlet>
This enables Angular to load components dynamically based on the URL — enabling Single Page Application (SPA) behavior.
Pipes are used to transform data in the template without altering the original source.
Example use: {{ birthday | date:’longDate’ }}
Common built-in pipes: date, uppercase, currency, etc.
You can create custom pipes too:
@Pipe({ name: ‘capitalize’ })
export class CapitalizePipe implements PipeTransform {
transform(value: string): string {
return value.charAt(0).toUpperCase() + value.slice(1);
}
}
Angular leans heavily on RxJS for reactive programming.
Use observables to handle async tasks like HTTP requests or user input:
this.http.get(‘/api/data’).subscribe(response => {
this.data = response;
});
Mastering RxJS operators like map, switchMap, filter is key to advanced Angular development.