Angular JS is a JavaScript framework used for building single-page applications. It uses MVC architecture with models for data, views for displaying data, and controllers for logic. The document discusses key Angular JS concepts like directives, expressions, controllers, filters, tables, modules, forms, includes, views, and internationalization. Directives extend HTML, expressions bind data to HTML, and controllers control interactions. Modules separate code into logical units. Forms provide data binding and validation. Views allow single-page applications with multiple views on one page.