What is GetX in Flutter?

GetX is a lightweight, all-in-one package that combines state management, dependency injection, and route management. For state, it uses Rx variables (reactive) with the Obx widget for automatic rebuilds, or GetBuilder for simpler manual updates. Navigation works without BuildContext: Get.to(Screen()). Dependency injection: Get.put(Controller()). GetX is popular for its minimal boilerplate, but some developers prefer BLoC or Riverpod for their more explicit, testable patterns.