TweenInfo is the object that describes HOW an animation happens in TweenService: duration, easing style, direction, repeat count, whether it reverses and the initial delay. It doesn't say what to animate (that's the goal, a table of properties), only the rhythm. The full signature is TweenInfo.new(time, EasingStyle, EasingDirection, repeatCount, reverses, delayTime), and only time is required.