The budget is usually presented in a tabular form, listing the resource requirements for a successful execution of the project. Any position in this budget must be justified (linked to an objective, work package or activity) and explained (cost structure). The maximum amount of found is given by the donor.
The categories for which funding may be requested usually comprise at least the four positions of Personnel, Equipment, Supplies, and Travel. Your budget must be transparent (why you request how much money for which position), requiring that each and every position is justified (indicate why this item is required for a given activity and in what way is will contribute to a milestone, a deliverable or the overall goal of your research) and explained (cost composition and structure with supporting offers, proforma or official quotes for the requested funding items).