Breakdowns are special keys that maintain proportional time relationships with adjacent keys. For example, as shown in the figure below, if you move the key at time 11 forward along the timeline to speed up an action, the breakdown at time 17 also moves forward to maintain a smooth transition to the key at 24, which is not moving.
Use Breakdowns to adjust the timing of an animation while holding attribute values at points on the animation curve. Breakdowns are green ticks on the Time Slider and green points in the Graph Editor.
Breakdowns that do not have adjacent keys are unbounded. These work like regular keys when you place, edit, and move them. Breakdowns have editable tangents. When one or more Breakdowns are bounded by regular keys, the Breakdowns modify their position in time to reflect any changes to the time positions of the regular, bounding, keys. For more information, see Set Breakdowns.