A budget is a microeconomic concept that shows the trade-off made when one good is exchanged for another. In terms of the bottom line—or the end result of this trade-off—a surplus budget means profits are anticipated, a balanced budget means revenues are expected to equal expenses, and a deficit budget means expenses will exceed revenues.

Budgeting is the personal finance tool for taking control of your money. A budget is a written plan for how you will spend your money. It allows you to make financial decisions ahead of time, which makes it easier to cover all your expenses along with paying off debt, saving for the future, and being able to afford fun expenses.