Bluetooth chip, is included in the MCU. Because he wants to run the Bluetooth protocol stack, as well as audio, data, and so on. But the resources are stronger; But there is a difference between the two, and the difference lies in the emphasis; (1) Bluetooth chip is mainly an SOC system that completes Bluetooth functions. The single chip microcomputer is a universal chip, dealing with control and so on; The two applications are different; (2), the Bluetooth chip is generally more expensive, because its resources are relatively rich. The MCU is relatively cheap because of its few resources; 2, why will Bluetooth chip attached to a single chip computer? ; (1), the Bluetooth chip is generally more complex, so many companies on the market, the Bluetooth chip into a module, and then encapsulate some of the Bluetooth underlying functions, and then set aside the serial port, or spi, or iic and so on interface, so that users use the single chip computer to control; (2) In this way, when developing the project, you do not need to care about the related terms of Bluetooth, and concentrate on doing your own application. Just like the KT1025A