Areas and area tags are separate but related Revit components.
Areas are model elements in Revit, like walls and doors. Area tags are annotation elements that you can add to area plan views.
When creating an early design, before you define walls or other bounding elements in a project, you can create an area schedule. In the schedule, add information about the areas that you plan to use. Later, you can place these predefined areas in an area plan of the project.