Task panes are helper windows that you can use to perform certain tasks, such as modifying HTML tag properties, adding ASP.NET controls and Web Parts to your pages, and managing cascading style sheets. You can open, close, and move task panes to the sides of the SharePoint Designer program window or make them float so that they appear in the middle of the program window. When you first open SharePoint Designer, only four task panes open and are placed on the right and left sides of the SharePoint Designer program window. Other task panes can be opened from the Task Pane menu. SharePoint Designer provides you with 24 task panes, listed in the following table.
Displays the contents of a SharePoint site. ...