Timelines use Tracks to define the animation of a single piece of data. This can be a float value, vector value, color value, or events. Tracks can be added to the Timeline by clicking one of the Add Track buttons. For instance, click the button and enter a name for the new track.
Press Enter to save the name for your new float track.
Track Name - You can enter a new name for the track into this field at any time.
External Curve group - Allows you to choose an external curve asset from the Content Browser instead of creating your own curve.
Track timeline - This is the keyframe graph for this track. You will place keyframes into this and see the resulting interpolation curve.