Budget categories are the specific groupings used to organize and track spending within a budget, such as housing, food, transportation, entertainment, and savings. Assigning every dollar to a category gives you a clear picture of where your money is going and makes it easier to identify areas of overspending. Most budgeting systems are built around category-based tracking. Choosing the right level of detail for your categories is key: too broad and you lose insight, too granular and the system becomes burdensome to maintain.