Ext JS (Sencha Ext JS) is a powerful JavaScript framework used for building enterprise-grade, data-intensive web applications with rich user interfaces. It enables developers to create highly interactive and responsive applications with built-in UI components, data management tools, and architectural patterns. This training explains core concepts such as components, layouts, data binding, stores, and MVC/MVVM architecture. It also covers advanced grids, charts, theming, performance optimization, and integration with backend services. You will learn how enterprises use Sencha Ext JS to build scalable dashboards, admin portals, and business-critical applications. The course also highlights best practices for developing maintainable, high-performance, and production-ready web applications.