This is the fundamental class which lets you accomplish basic Bluetooth tasks such as device discovery etc. You can get the adapter by calling:

// Initializes Bluetooth adapter. final BluetoothManager bluetoothManager =         (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE); mBluetoothAdapter = bluetoothManager.getAdapter();

This BluetoothAdapter is universal and the application can interact with it to transfer and receive data over the Bluetooth link. You can also find methods like startLeScan() and stopLeScan()in this class, which will then be implemented using classes of LeScanCallbackinterface.