## glossary

What is Angular?

Angular is a web application framework maintained by Google, released in 2016 as a complete rewrite of AngularJS (2010). Unlike React and Vue, it is deliberately complete: router, HTTP client, forms, validation, dependency injection and a command-line tool all come in the box.

The choice is philosophical. Where React delivers freedom and demands decisions, Angular delivers decisions and demands adherence. In large organizations, with many teams and turnover, that standardization is worth more than the flexibility.

TypeScript is not optional

Angular is written in TypeScript and assumes you use it. Decorators like @Component and @Injectable are part of the framework’s syntax, and strong typing runs through everything from forms to HTTP responses.

A component and an injected service

@Injectable({ providedIn: 'root' })
export class PedidoService {
  constructor(private http: HttpClient) {}

  listar(): Observable<Pedido[]> {
    return this.http.get<Pedido[]>('/api/pedidos');
  }
}

@Component({
  selector: 'app-pedidos',
  template: '<li *ngFor="let p of pedidos">{{ p.cliente }}</li>',
})
export class PedidosComponent implements OnInit {
  pedidos: Pedido[] = [];

  // Angular delivers the instance automatically
  constructor(private service: PedidoService) {}

  ngOnInit() {
    this.service.listar().subscribe((r) => (this.pedidos = r));
  }
}

Concepts you need to master

Dependency injection — the framework instantiates and delivers the services, making testing and decoupling easier.
RxJS and Observables — asynchronous flows are handled as streams, not as Promises. It is the biggest entry barrier.
Modules and standalone components — how the code is organized; recent versions made modules optional.
Change detection — the mechanism that decides when to update the screen, tunable for performance gains.
Angular CLI — generates components, services and builds with one command, standardizing the structure.

Where it pays off — and where it does not

Angular shines in long-lived corporate systems: ERPs, banking platforms, complex admin panels, teams of dozens of people. It loses in small projects, prototypes and content sites, where the upfront weight and the RxJS learning curve never pay for themselves. If the goal is a landing page or a blog, another framework will almost certainly ship sooner.

## faq

Frequently asked questions

What is the difference between Angular and AngularJS?

They are different frameworks that share a name. AngularJS (version 1.x) is from 2010, uses JavaScript and a two-way binding model with scopes. Angular (2 onward) is a 2016 rewrite in TypeScript, with a completely different architecture. There is no simple upgrade path between them.

Is Angular dying?

No. It lost ground to React in overall popularity and in startups, but remains strong in the corporate market and receives frequent updates from Google, including significant recent changes like signals and standalone components.

Do I need to learn RxJS to use Angular?

Yes, at least the essentials. The HTTP client returns Observables, and the router exposes parameters the same way. Mastering subscribe, map, switchMap and the async pipe in templates covers most everyday usage.