A sheet (also called a drawing sheet) is an individual page of a construction document set. In Revit LT, you create a sheet view for each sheet in the construction document set. You can then place multiple drawings or schedules on each sheet view.
Parts of a sheet
When you add sheets to a Revit project, they are listed in the Project Browser under Sheets (all).
Sheets are listed in the Project Browser
As you move a drawing or schedule onto a sheet, a viewport displays. A viewport is a representation of the drawing or schedule when it is placed on a sheet.