ODM, or Original Design Manufacturing, refers to a producer/reseller relationship in which the full specifications of a project are determined by the reseller, rather than based on the specs established by the manufacturer.
An ODM is a company that takes the original specifications of another company or individual and builds the design to the product specifications.
ODMs make it possible for a customers to get a product to market without having to completely design the hardware and without investing in production facilities. The ODM supplies manufacturing capacity and creates the specification typically retains ownership of the design.
The ODM typically builds the equipment from commercial off-the-shelf (COTS) components that can be customized to some extent for particular environments. Although an organization could possibly do the same thing in-house, the ODM can manufacture and deliver customized servers faster and may also offer warranty protection for parts.