Angular 2 is a complete rewrite of AngularJS, a popular open-source web application framework developed by Google. Released in 2016, Angular 2 is a platform for building dynamic, single-page web applications (SPAs) using TypeScript, a statically typed superset of JavaScript. It introduces a component-based architecture, where the UI is built using reusable components, making it more modular and maintainable than its predecessor. Angular 2 also improves performance with features like a more efficient change detection system and enhanced dependency injection. It's widely used for building modern web applications, offering tools for routing, forms, HTTP handling, and more.