What is an ODM?
An Original Design Manufacturer (or ODM) is a manufacturer of anything (in this case laptops) that primarily sells their products to other companies which will sell the products under their own brand name. Most smaller laptop brands in the 1990s were selling generic designs from an ODM rather than manufacturing in-house. I refer to these brands that sold rebadged ODM laptops "resellers" or "vendors".
ODM manufacturers did sometimes sold their laptops under their own brand name. One example of this is Twinhead, which had a fairly large brand presence. Others, like Quanta or Nan Tan essentially never did.
Virtually every laptop ODM was/is based out of Taiwan. They captured most of the market in the early days and have held it through today, although these days their factories are usually in mainland China.
It is worth noting that just because one brand's laptop was manufactured by an ODM, that doesn't mean that the ODM did all the design for it. These days, pretty much every major laptop company, including Dell, HP, Lenovo, and others, contract ODMs to do their manufacturing. Quanta, Compal, Wistron, and Inventec are four of the largest ODMs today (as of 2025). These laptops are still designed by Dell/HP/etc, but it's just cheaper to have an ODM handle the manufacturing and circuit design.