Original equipment manufacturer

Original equipment manufacturer (OEM) is a company that makes a part or subsystem that is used in another company's end product. For example, if Acme Manufacturing Co. makes power cords that are used on IBM computers, Acme is the OEM.

However, the term is used in several other ways, which causes ambiguity. It sometimes refers to the maker of a system that includes other companies' subsystems, an end-product producer, an automotive part that is manufactured by the same company that produced the original part used in the automobile's assembly, or a value-added reseller.

Automotive parts

When referring to auto parts, OEM refers to parts and manufacturers involved in the final assembly of a vehicle—in contrast to aftermarket parts that can be installed after the car comes out of the factory. For example, if Ford used Autolite spark plugs, Exide batteries, Bosch fuel injectors, and Ford's own engine blocks and heads when building a car, then car restorers and collectors consider all of those brands as OEM brands, in contrast to aftermarket brands (such as Champion plugs, DieHard batteries, Kinsler fuel injectors, and BMP engine blocks and heads). This can mean that Bosch injectors, for example, are considered OEM parts on one car model and aftermarket parts on another model.