control point

Control points are a type of motion point. You add control points to a motion path when you want to change a peg's motion, but you are not concerned that it change at an exact frame.

You can add control points at any position on the motion path. This is different from a keyframe, which locks to a specific frame number in your animation.

You can add control points to a motion path using any of the following methods:

Use the Motion tool, press [Shift] and click the motion path to add a control point.
Click the Add button on the Motion Point tab. In the Add Motion Point dialog box, select Control Point from the Point Type drop-list and type the frame number for this control point in the Frame field. Then click OK.
Select a keyframe and de-select the Lock in Time option on the Motion Point tab.

You can change the properties of the motion around a point by modifying the Tension, Continuity and Bias values in the Motion Point tab.