AngularJS is a JavaScript framework that extends HTML with directives and binds data to HTML with expressions. Some key points:
- AngularJS extends HTML with directives like ng-app, ng-model, and ng-bind.
- Expressions written with double braces like {{expression}} output data on the HTML page.
- Modules define AngularJS applications and controllers control the application logic and data.
- Common directives include ng-init, ng-click, ng-repeat, and filters like currency and lowercase can be used.
- A shopping cart example demonstrates binding data with ng-repeat, adding items with ng-click, and removing with ng-click.