It is usually unnecessary to modify the properties of a content area. However, if you are designing a form that contains subforms that are set to flow content, becoming familiar with the properties of content areas will help you to understand the behavior of subforms.
Content areas cannot be selected or manipulated through the Design View tab of the Layout Editor. If required, you can select, cut, copy, paste, move, delete, or resize content areas through the Master Pages tab of the Layout Editor. A rectangle on the master page delimits the area bounded by a content area.
Livecycle contentareas task.40.2.1 Overview of content areas
New forms have a default content area. If required (for example, when designing a form that contains subforms set to flow content), you can add additional content areas to the form. All content areas are displayed in the Hierarchy palette.
Livecycle contentareas task.40.2.2 Overview of content areas
See also 

Overview of content areas