Key timing and easing in and out of a key are parameters that you can adjust with tools on the Motion panel, for example. The Motion panel also provides an alternative to Track View for assigning animation controllers.
Additional rollouts display in the Motion panel if an assigned animation controller has parameters. If a Path constraint is assigned to the position track of an object, then a Path Parameters rollout is added to the Motion panel. A Link constraint displays a Link Parameters rollout, a Position XYZ controller displays a Position XYZ Parameters rollout, and so on.
Trajectories
Click Trajectories to chart a path that an object will travel along in the viewports. Yellow dots along the path represent frames, giving you an idea of velocity and easing. By turning on Sub-Object Keys, keys can be moved in space, key properties can be changed, the trajectories will reflect all the adjustments you make. You can also convert to and from splines and collapse transforms using trajectories.
Interface
Parameters
Provides an alternative to Track View for adjusting transform controllers and key information.
Assign Controller Rollout
PRS Parameters Rollout
Key Info (Basic) Rollout/Dialog
Key Info (Advanced) Rollout/Dialog
Trajectories
Provides tools for working with objects' trajectories.