An original equipment manufacturer (OEM) is generally perceived as a company that produces parts and equipment that may be marketed by another manufacturer. The term is also used in several other ways, which causes ambiguity. It sometimes means 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.[1][2]
Many customers, such as the Department of Defense, wanted to buy complete systems, all put together and ready to run with the turn of a key; hence the rise of companies known as original equipment manufacturers, or OEMs—they'd buy gear from various companies and put it together in packages.