include _util-fns :marked The **QuickStart playground** is the easiest way to discover Angular. You don't need to install anything. Just click the image below, launch the live-coding environment, and start entering code. The QuickStart displays a super-simple Angular component, written in [TypeScript](#typescript): +makeExample('app/app.component.ts','','app/app.component.ts')(format='.') :marked Angular applications are made of _components_. A _component_ is the combination of an HTML template and a component class that controls a portion of the screen. Every component begins with a `@Component` [_decorator_](glossary.html#decorator '"Decorator" explained') function that takes a _metadata_ object. The metadata describe how the HTML template and component class work together. The `selector` property tells Angular to display the component inside a custom `` tag in the `index.html`. +makeExample('index.html','my-app','index.html (inside )')(format='.') :marked The `template` property defines a message inside an `

` header. The message starts with "Hello" and ends with `{{name}}` which is an Angular [interpolation binding](guide/displaying-data.html) expression. At runtime, Angular replaces `{{name}}` with the value of the component's `name` property. Change the component class's `name` property from `'Angular'` to `'World'` and see what happens. Binding is one of many Angular features you'll discover in this documentation. .l-sub-section :marked ### Next step This QuickStart playground is fine for exploring Angular but you won't develop a real application there. You'll want to develop locally on your own machine. Visit the [**setup guide**](guide/setup.html "Install Angular for local development") to learn how. .l-main-section a#typescript :marked ## TypeScript This example is written in TypeScript, a typed super-set of the latest JavaScript. TypeScript compiles into JavaScript that runs on any modern browser. Most developers find it delightful which is why most Angular developers write applications in TypeScript. You can write your application in [other versions of JavaScript](cookbook/ts-to-js.html "TypeScript to JavaScript") if you prefer. // [Dart](../../dart/latest) or Dart if you prefer.