Angular Web Framework

Angular is a free and open-source TypeScript-based web application framework led by Google. Originally created by Misko Hevery (as AngularJS, released 2010) and completely rewritten as Angular 2 (September 2016), the framework is now on a six-month release cycle. Used by Google (Cloud Console, Analytics, Ads), Microsoft, IBM, and many enterprises. Key features: TypeScript-first: built in TypeScript with strict type checking, decorators, and interfaces. Component architecture: applications are built from components with TypeScript classes, HTML templates, and CSS styles. Components form a tree with data flowing via @Input and events via @Output. Templates: extend HTML with directives (ngIf, ngFor, ngSwitch), pipes (uppercase, date, async), and two-way binding ([(ngModel)]). Dependency injection: powerful hierarchical DI system where services are injected into components. Providers configured at root, module, or component level, enabling testability and loose coupling. RxJS: uses Reactive Extensions for async operations and data streams. HttpClient returns Observables. Router: full client-side router with lazy-loaded routes, guards (CanActivate, CanDeactivate), resolvers, and child routes. Forms: Template-driven (FormsModule) and Reactive Forms (ReactiveFormsModule) with validation and custom validators. Angular CLI: scaffolding (ng generate), building (ng build), testing (ng test with Karma/Jasmine), serving (ng serve). Standalone components (Angular 14+): components without NgModule. Signals (Angular 16+): fine-grained reactivity. MIT.