A budget is a spending plan - for the government, a company, a non-profit, or even an individual.
A budget allows you to put ideas down on paper in terms of the monetary value involved with a project. For businesses and various projects, it also provides a forecast into their financial performance going forward. This way, the actual and forecasted operations can be measured against each other.
Used properly, a budget can identify the amount of money that one would require at a certain point of time in the future. This is useful because allocation of capital eventually ends up having an impact on the direction of the project. Sometimes, realities of the budget force people to rethink plans drastically, even cull certain projects.
Budgets can be categorized based on their purpose:
Budgets can be classified by their methodology, that is used to come up with the data:
Another popular way of classifying blogs is by the kinds of budgets used: