A budget is a financial estimate prepared for a specific future period, guiding actions for organizations, such as businesses and governments. Budgets can be classified by time (long-term, short-term, current) and flexibility (fixed, flexible) and serve various functions including sales, purchase, production, and cash forecasting. Budgetary control involves planning and comparing actual outcomes to budget forecasts to enhance profitability and operational efficiency, but it can face limitations due to uncertainties and interdepartmental coordination challenges.