In business, overhead or overhead expense refers to an ongoing expense of operating a business. Overheads are the expenditure which cannot be conveniently traced to or identified with any particular revenue unit, unlike operating expenses such as raw material and labor. Therefore, overheads cannot be immediately associated with the products or services being offered, thus do not directly generate profits. However, overheads are still vital to business operations as they provide critical support for the business to carry out profit making activities. For example, overhead costs such as the rent for a factory allows workers to manufacture products which can then be sold for a profit. Such expenses are incurred for output generally and not for particular work order; e.g., wages paid to watch