AngularJS is a JavaScript MVC framework developed by Google to facilitate building maintainable web applications, focusing on enhancing HTML through the use of directives and improving the architecture of web apps. It promotes best practices like Test-Driven Development (TDD) and supports single-page applications with features such as two-way data binding, dependency injection, and routing. The framework emphasizes a declarative programming style over imperative coding and provides a refined way to manage application functionality through its component-based architecture.