AngularJS is a cross-platform development framework written in pure JavaScript. Its main goal was to provide a simple but powerful framework for developers to create rich single-page applications. Angular introduced many powerful features including Dependency Injection to create testable code. Its flexibility makes it a popular choice for enterprise applications. The framework is easy to learn and is designed for rapid development. It also has a large community of enthusiasts.

Components are the basis of an Angular application. Every component has a corresponding class and HTML template. The component is marked with a decorator. The decorator adds metadata to the class and instructs Angular to use it. For instance, the metadata of a component class is associated with its HTML template. This allows Angular to modify the HTML, which improves readability. The service class’s metadata provides the information a component needs to make it available to other components through dependency injection.

Angular also offers two-way data binding. Property binding lets the application respond to user input. Event binding allows the application to interpolate data into HTML. Angular automatically evaluates directives in a template and modifies HTML elements. The two-way data binding feature allows the changes in the DOM to affect the data in the program. The main advantage of using Angular is its reusability. You can modify the HTML and DOM as you wish.