This HC-05 Bluetooth RF transceiver module can be set as a transmitter or receiver. It can easily transfer data wirelessly, without complex PCB layout or deep knowledge in the Bluetooth software stack. You can combine this Bluetooth module with your MCU, ARM or DSP systems, SOC systems, Personal Digital Assistants (PDAs), Computer Accessories or other systems your want to use under Bluetooth functions.
The HC-05 Bluetooth module can connect to other modules in two ways: As a master, or as a slave. For example, a robot can be designed to be a master connected to a slave Bluetooth module or as a slave board to make a wireless connection with a PC.