Scenarios are used for running a sequence of simulations, typically when you want to use the same model for different sets of input data - perhaps for different geographical locations.
You can also use scenarios to experiment with solver settings or to run a sequence of different sensitivity analyses.
Scenarios are defined and listed in the context screen behind the scenario button.
This panel allows you to create a list of scenarios and to select which parameters/lookup tables have different data for different scenarios. The actual data is then entered in the time series screen and parameters screen respectively.
This panel also let you specify individual settings for each scenario.