OEM refers to the mode that the brand company is responsible for designing and developing products and the OEM is responsible for processing and production. This is the result of economic globalization and social division of labor. Due to factors such as supply chain and production cost, international brand manufacturers in Europe and America often do not produce their own products, but entrust their manufacturers to foundries in countries and regions with lower production costs, such as Chinese mainland, Taiwan Province, Southeast Asia, Mexico and South America. Like Apple, Samsung, HTC, Nokia and so on. This model is also based on this model.
There are many foundries in Shenzhen and Dongguan. Well-known are Foxconn (Apple, Blackberry, Xiaomi, etc. ), BYD (Nokia, Huawei P6, IUNI, etc.), Inventec (Xiaomi), Crown (Sony, LG, etc. ), Flextronics (formerly motorcycle OEM in Tianjin). As for the pattern, it's really hard to say. High-end products must be produced by these big companies, and Foxconn must be used by Apple. Low-end products are basically based on cost, and products are found in foundries.