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 (NgModules)
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:
Here’s a basic example:
@NgModule({
declarations: [AppComponent],
imports: [BrowserModule],
bootstrap: [AppComponent]
})
export class AppModule {}
Components
Components are the heart of the UI. They are the building blocks of any Angular application. Each screen, button, form, or layout is typically a component.
A component includes:
Here’s a basic example:
@Component({
selector: 'app-hero',
templateUrl: './hero.component.html',
styleUrls: ['./hero.component.scss']
})
export class HeroComponent {
@Input() name: string;
}
Templates & Data Binding
Templates define how your UI looks. Angular’s powerful binding system connects your logic to the view:
{{ title }}
→ Interpolation[src]="imageUrl"
→ Property Binding(click)="onClick()"
→ Event Binding[(ngModel)]="formValue"
→ Two-way BindingThis makes your UI reactive and dynamic.
Directives
Directives let you extend HTML with custom logic or behavior.
*ngIf
, *ngFor
[ngClass]
, [ngStyle]
Routing
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
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
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);
}
}
RxJS & Observables
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
, and filter
is key to advanced Angular development.