Scenarios
Modelling a decision — a move, a sabbatical, a purchase — against your actual position rather than a blank spreadsheet.
A scenario projects forward from where you actually are. That is the difference from doing it in a spreadsheet: the starting point is your real net worth and your real income and expenses, not numbers you retyped and will not maintain.
Building one
A scenario has a name and a window, and inside it a list of change events: things that happen on a date and alter the trajectory. Income starting or stopping, a recurring cost beginning, a lump sum in or out, a category's baseline shifting.
You can set a scenario's baseline from your existing category behaviour, so the projection starts from what you actually spend rather than from an estimate of it.
Reading one
The output is your net worth projected over the window, with the events applied. The value is comparison rather than prediction: the same question with and without the sabbatical, two scenarios side by side, is a much better instrument than either number on its own.
Duplicating
Duplicate a scenario and change one thing. That is the intended workflow, and it is why duplication exists as its own action.
What it is not
Not a forecast, and not advice. It applies your assumptions arithmetically and carries them forward. Markets, inflation and your own behaviour are not modelled, and the output is only ever as good as the events you put in.