A budget surplus occurs when:

Revenue exceeds expenditure
Expenditure exceeds revenue
Revenue equals expenditure
The budget is delayed

A budget surplus occurs when revenue exceeds expenditure. This means that the government collects more money in taxes and other revenue than it spends on goods and services, programs, and interest on the national debt. A budget surplus can be used to reduce the national debt, invest in infrastructure or other programs, or provide tax cuts.

A budget deficit occurs when expenditure exceeds revenue. This means that the government spends more money than it collects in taxes and other revenue. A budget deficit can be financed by borrowing money, which increases the national debt.

A balanced budget occurs when revenue equals expenditure. This means that the government neither borrows money nor has a surplus. A balanced budget is often seen as a goal of fiscal policy, but it is not always possible to achieve.

A delayed budget occurs when the government does not pass a budget by the start of the fiscal year. This can happen for a variety of reasons, such as political gridlock or a natural disaster. A delayed budget can have a number of negative consequences, such as disruptions to government services and uncertainty for businesses.