A circular reference is a chain of references that circles back to the original object. In spreadsheets it is a string of 1 or more formulas, each formula referencing the next formula, and the last one referencing the first formula. The problem is how to compute the formulas. By default, such a set of formulas is considered an error, and the values returned by all the formulas in the circular reference are error values. An alternative approach is to find a solution, such that the formulas compute a consistent set of results (to a certain precision).
Whitebirch represents a revolution in financial modeling. Rather than working with an ever-increasing number of individual cells, and maintaining all of the formulas that tie them together, Whitebirch Enterprise Planning introduces Financial Objects.
An easy way to think about financial objects is as a group of related line items, like units sold, selling price per unit and revenue that work together to perform a task, such as calculate revenue from selling price and units sold.
Not all scenario/"what if" capabilities are created equal. Most people think of "what if" analysis as taking a variable and changing it to different values to see how the output, such as Net Income or Cash Balance, changes. One might also want to change multiple variables and compare the results. Each set of values results in a new "scenario". Excel has a feature called "Scenario Manager" that allows cells to have different values for different scenarios, and will create a summary of the results or a pivot table. However, a maximum of 32 cells can be changed as part of a scenario.