# Model Preparation Steps

Specifying a model is how the user may fully describe what reactions to simulate. The Editor Window serves as a workspace for graphically describing molecules, chemical species and the involved reactions. Once the workspace depicition reflects the desired model picture of each object, the object may be dragged and dropped onto the appropriate Palette Window. This action serves to register the graphically created objects with their respective internal databases, and allows the user the build up a library of each type of object. Molecules, species and reactions registered in their respective Palette Windows may then be dragged and dropped back onto the Editor Window as needed to build up increasingly larger complexes and reactions.

Each of the following four steps are needed to fully prepare a BioNetGen model. Molecules and reaction rules require creation graphically on the Editor Window, whereas registering species and observables may be done by selecting single molecules, or groups of molecules, and dropping onto the Species or Observables Palette Windows accordingly.

- Creating molecules
- Specifying chemical species
- Creating reaction rules
- Specifying observables