Final answer:
Controllable costs are the expenditures that a manager can influence through their decisions and actions, unlike fixed costs like rent which remain constant regardless of output.
Step-by-step explanation:
Costs that can be influenced by a manager's decisions and actions are called controllable costs. In contrast to fixed costs, which are expenditures that do not change regardless of the level of production, controllable costs can be adjusted by a manager. For example, while the rent on a factory (a fixed cost) cannot be easily changed in the short run, items such as supply expenses or overtime pay (controllable costs) can be managed based on output needs. It's also important to understand the concept of "spreading the overhead", which refers to allocating fixed costs over an increasing number of units produced, thereby reducing the average fixed cost per unit.