| Main model |
The parts of the building model that are not defined using design options. The main model is the entire building model, excluding any design options. |
| Design option set |
A collection of alternatives that addresses a particular design problem, such as a lobby or a floor layout. See Creating Design Option Sets. |
| Design option |
One possible solution to the design problem. See Adding Design Options and Working with Design Options. |
| Primary option |
The preferred design option in the design option set. The primary option has a closer relationship to the main model than secondary options. Elements in the main model and in the primary option can reference each other. Only one design option in a set can be the primary option. All other options are secondary. By default, each project view displays both the main model and the primary option for each set. See Promoting a Secondary Option to the Primary Option. |
| Secondary option |
A design option that is an alternative to the primary option in the set. Elements in a secondary option can reference elements in the main model. However, elements in the main model cannot reference elements in a secondary option. See Referencing Elements in Design Options. |
| Active option |
The design option that you are currently editing. See Editing a Design Option and Determining the Active Option. |
| Dedicated view |
A view that is dedicated to a specific design option. When this view is active or added to a sheet, Revit shows the design option along with the main model. See Dedicating Views to Design Options. |