What is the difference between direct and indirect expenses?

Direct Expenses are those costs directly related to the principal activity of the business. Examples include the raw materials used to manufacture a product and the labor costs associated with the work performed to produce the product. Indirect Expenses are those not directly related to the principal activity of the business. Examples include Sales activities, Research and Development activities, and Administrative activities. Simple example: An auto repair business. Direct Expenses would include parts purchased from a vendor to repair an automobile and the labor costs associated with the mechanic who performed the actual repair. Indirect Expenses would include the auto repair shop's advertising costs and the labor costs of the front office receptionist.