"Original equipment" or "OEM" are antonyms for the word "aftermarket". The term "original equipment" refers to components, parts, or accessories that come directly from the vehicle manufacturer. These products are designed to fit perfectly in the vehicle and are of high quality. On the other hand, the "aftermarket" refers to components, parts, or accessories that are manufactured by other companies that are typically not affiliated with the vehicle manufacturer. These products are made to fit multiple vehicles, are generally less expensive than OEM parts, and may not offer the same level of quality or warranty. Understanding the difference between OEM and aftermarket can help you make informed decisions when purchasing replacement parts or accessories for your vehicle.