What are the differences between AuxilliarySenorDesigner (driver) vs CustomSensorDesigner?

I noticed two blocks in InvenSense SensorStudio which appear to be very similar. hey are AuxillarySensorDesign (driver) and CustomSensorDesigner block. What is the difference between the two?

AuxilliarySenorDesigner

• Connect to device block (and not to sensor block)
• Does not support emulation
• Must be used to create driver sensors that get data from hardware (I2C)

CustomSensorDesigner

• Connect to one or several sensors block
• Support emulation
• Should be used to create virtual sensors that gets data from other sensors in the system and apply some algorithm

CustomSensor

• Connect to device block
• Used to retrieve sensor data from custom sensors from the device (after flashing a firmware)

Refer to "3.6. DESIGN YOUR SENSOR ALGORITHM", "3.7. SENSOR FRAMEWORK EXPLAINED" and "3.8. DESIGN YOUR SENSOR DRIVER" of 001 - SensorStudio User Documentation.pdf available with your SensorStudio installation