In the animation mode, the left panel displays a Scene tab that contains all available animations you created in the project. The bottom panel of the animation mode has two tabs: Timeline and Triggers - both are related to a particular animation selected from the Scene tree.
Timeline allows you to create animations for objects, including game-play sequences, and audio sequences. It represents a list of animation tracks and related keyframes.
A Trigger is an object that causes an animation to occur. The Triggers panel is designed to define particular conditions used to launch animations.