A budget is a quantitative expression of a plan for a defined period of time. It may include planned sales volumes and revenues, resource quantities, costs and expenses, assets, liabilities and cash flows. It expresses strategic plans of business units, organizations, activities or events in measurable terms. International Budget Partnership regularly monitors global budget information for the civil society.

A government budget is a government document presenting the government's proposed revenues and spending for a financial year that is often passed by the legislature, approved by the chief executive or president and presented by the Finance Minister to the nation. The budget is also known as the Annual Financial Statement of the country. This document estimates the anticipated government revenues and government expenditures for the ensuing (current) financial year. For example, only certain types of revenue may be imposed and collected. Property tax is frequently the basis for municipal and county revenues, while sales tax and/or income tax are the basis for state revenues, and income tax and corporate tax are the basis for national revenues.