The Task Pane is a docked area within the PowerPoint 2016 interface that provides more options than dialog boxes. Also, unlike most dialog boxes which cover the Slide Area, you can view both the active slide(s) and the Task Pane at the same time. The Task Pane, therefore, provides a more streamlined experience.
To learn more, choose your version of PowerPoint. If we do not have a tutorial for your version of PowerPoint, explore the version closest to the one you use.