The term budget refers to an estimation of revenue and expenses over a specified future period of time and is usually compiled and re-evaluated on a periodic basis. Budgets can be made for any entity that wants to spend money, including governments and businesses, along with people and households at any income level. To manage your monthly expenses, prepare for life's unpredictable events, and be able to afford big-ticket items without going into debt, budgeting is important.

Source: Investopedia