All visualizations in GenomeView are organized into tracks. A track typically holds on particular type of data or one particular data set. There can be multiple tracks of each type.
When loading new data, a new track is added.

On the right side of the window there is an overview of all tracks that are currently available.

You can reorder the tracks by dragging them up and down in this table, hide them by clicking the eye icon or remove them with the garbage bin icon.