ODMs or Original Device Manufacturers are manufacturers that create completed, ready-to-sell products to other companies. ODMs are also known as white-labelers.
It is important to note that the term ODM can be used to describe both companies that make devices, and the devices themselves.
An ODM designs and manufacturers unbranded products with the specific intent for it to be sold to other companies for it to be branded, packaged and sold to consumers.
One of the biggest ODMs in the consumer electronics category is Compal. They create ODM laptops for big companies such as Acer, Lenovo, Dell, HP, Toshiba among others.
While ODMs create finished devices that can be resold, OEMs (Original Equipment Manufacturers) create specific parts to create a finished product.