The HC-06 bluetooth module designed for wireless serial communication. It is a slave module meaning that it can receive serial data when sent out from a master bluetooth device e.g. smart phones, PC.
When the module receives wireless data, it is sent out through the serial interface exactly at it is received. No source code specific to the Bluetooth module is needed in the arduino chip. An app on the phone is used to send out inputs to the module which receives and then transfers this to the arduino. The arduino and actuators in turn responds accordingly, as specified in the source code.
When the module is not in a paired state, the LED on the module blinks rapidly whereas when paired with the app on the phone, the LED on the module is a steady red