Angular (often referred to as Angular 2+) is a complete rewrite of Angularjs by the same team at Google.
It is a modern framework for building large-scale, maintainable single-page applications (SPAs) using typography.

Note: AngularJS (1.x) and Angular (2+) are completely different frameworks

Why Angular Was Rewritten?

AngularJS (1.x) had the following issues:

• Performance bottlenecks with large apps
• Complex digest cycles and two-way binding
• Lack of modern tooling support

Angular (2+) addressed these issues in the following ways:

• Improved performance
• Mobile-first design
• Modular and scalable architecture

Key Concepts in Angular 2+ (Compared to Angularjs)

Key Features of Angular 2+ and Beyond

Component-Based Architecture

Everything is a component (like React), which makes UI development modular and reusable.

@Component({
 selector: 'app-hello',
 template: '<h1>Hello {{name}}</h1>'
})
export class HelloComponent {
 name = 'Angular';
}

TypeScript Support

Angular uses TypeScript, which brings:

• Static typing
• Modern ES features
• Better tooling with IDEs

Modules and Lazy Loading

Apps are split into NgModules, allowing for lazy loading and better code organization.

@NgModule({
 declarations: [AppComponent],
 imports: [BrowserModule],
 bootstrap: [AppComponent]
})
export class AppModule {}

Improved Routing

Angular's router supports:

• Nested routes
• Guards (authentication protection)
• Lazy loading modules

RxJS and Observables

Used for reactive programming (for example, asynchronous data management from APIs).

this.http.get('api/data').subscribe(data => {
 this.items = data;
});

CLI Tooling (Angular CLI)

Official CLI to generate code, build, test, and deploy applications.

ng new my-app
ng generate component header
ng serve

Performance Features

• Ahead-of-time (AOT) compilation
• Change detection optimization
• Tree-shaking to remove unused code

Angular Versions Beyond 2

Also, read: Explain Security considerations in AngularJS applications