overhead
In business accounting, overhead is general operating expenses, including such items as heat and electricity for the premises, that have no direct relationship to the production or selling of a company's goods and services. In computers, overhead refers to the processing time required by system software, which includes the operating system and any utility that supports application programs. Overhead sometimes describes the amount of processing time the installation of a particular feature will add to the amount already required by the program. In telecommunications, overhead refers to the processing time required by codes for error checking and control of transmissions.