What is AnimationController in Flutter?

AnimationController is the core class that drives animations in Flutter. It generates values between 0.0 and 1.0 over a specified duration and requires a vsync parameter (usually the State class implementing TickerProviderStateMixin) to synchronize with the screen refresh rate. Use .forward() to play forward, .reverse() to play backward, and .repeat() to loop. Always call controller.dispose() in the widget's dispose() method.