These toolbars are visible or available the Curve Editor is open, and in general contain controls for editing animation data in the form of function curves.
Several different Curve Editor layouts are available: Default, Function Curve Layout, Trackbar Layout, and Function Curve Layout (Classic). The standard Function Curve Layout provides a streamlined interface designed for efficient function-curve editing, while the Function Curve Layout (Classic) offers more tools by default in a familiar arrangement.
To change to a different layout or save a custom one, right-click an empty toolbar area and choose Load Layout/Save Layout.
The default layout displays the following toolbars along the top of the Curve Editor:
The Function Curve Layout is the standard layout appearing by default when you open Track View in Curve Editor mode. It displays the following toolbars along the top and bottom of the editor:
Also, the standard layout has Filters > Show > Hierarchy off by default, while it's on in the classic layout.
The Trackbar Layout displays the following toolbars along the top of the editor:
The Function Curve Layout is the standard layout appearing by default when you open Track View in Curve Editor mode. It displays the following toolbars along the top and bottom of the editor: