Angular is a platform and framework for building single-page client applications using HTML and TypeScript. Angular is written in TypeScript. It implements core and optional functionality as a set of TypeScript libraries that you import into your apps.
The architecture of an Angular application relies on certain fundamental concepts. The basic building blocks of the Angular framework are Angular components that are organized into NgModules. NgModules collect related code into functional sets; an Angular app is defined by a set of NgModules. An app always has at least a root module that enables bootstrapping, and typically has many more feature modules.
Components define views, which are sets of screen elements that Angular can choose among and modify according to your program logic and data.
Components use services, which provide specific functionality not directly related to views. Service providers can be injected into components as dependencies, making your code modular, reusable, and efficient.
Modules, components and services are classes that use decorators. These decorators mark their type and provide metadata that tells Angular how to use them.
The metadata for a component class associates it with a template that defines a view. A template combines ordinary HTML with Angular directives and binding markup that allow Angular to modify the HTML before rendering it for display.
The metadata for a service class provides the information Angular needs to make it available to components through dependency injection (DI).
Angular JS and all the other version which came up over time has been designed as a type script based. This java-based framework programming was developed to help developers working on web-based application developments. Angular help improve the designing, development and testing of single page web applications. The use of Angular drastically reduces the turn-a-round time required for the application developments in comparison to the traditional HTML development approach. The Angular framework provides excellent client-side MVC to better control and programming of the web applications.