Information about layouts is stored in instances of the AcDbLayout class. A layout object contains the printing and plotting settings information needed to print the desired portion of the drawing. For example, a layout object contains the plot device, media size, plot area, and plot rotation, as well as several other attributes that help define the area to be printed.
AcDbLayout objects are stored in the ACAD_LAYOUT dictionary within the named object dictionary of the database. There is one AcDbLayout object per paper space layout, as well as a single AcDbLayout for model space. Each AcDbLayout object contains the object ID of its associated AcDbBlockTableRecord. This makes it easy to find the block table record in which the layout's actual geometry resides. If an AcDbBlockTableRecord represents a layout, then it contains the object ID of its associated AcDbLayout object.
Most of the plot information for layout objects is stored in AcDbPlotSettings, the base class of AcDbLayout. You can create named plot settings and use them to initialize other AcDbLayout objects. This allows you to export and import plot settings from one layout to another. These named plot settings are stored in instances of the AcDbPlotSettings class. There is one AcDbPlotSettings object for each named plot setting and they are stored in the ACAD_PLOTSETTINGS dictionary within the named object dictionary.