When you create a layout, you can choose to apply the information from an existing template.
A layout template is a layout imported from a DWG or DWT file. The program has sample layout templates to use when you design a new layout environment.
When you create a layout based on a template, the page setup and paper space objects, including any viewport objects, are used in the new layout. No model space objects are imported.
The layout templates are identified with a .dwt file extension. However, a layout template or layout from any drawing or drawing template can be imported into the current drawing.
Any drawing can be saved as a drawing template (DWT file), including all of the objects and layout settings. You can save a layout to a new DWT file by choosing the Save As option of the LAYOUT command. The template file is saved in the drawing template file folder as defined in the Files tab (Options dialog box). The layout template has a .dwt or .dwg extension like a drawing template or drawing file, but it contains little information not essential to the layout.
When you create a new layout template, any named items, such as blocks, layers, and dimension styles, that are used in the layout are saved with the template. These definition table items are imported as part of the layout settings if you import this template into a new layout. It is recommended that you use the Save As option of the LAYOUT command to create a new layout template. When you use the Save As option, unused definition table items are not saved with the file; they are not added to the new layout into which you import the template.
If you insert a layout from a drawing or template that was not created using the Save As option of the LAYOUT command, definition table items that are used in the drawing but not in the layout are inserted with the layout. To eliminate unnecessary definition table items, use the PURGE command.