Electronically, there are three main building blocks:
- Central processing unit to handle signal flows at various levels.
- A/D and D/A converters (stand for Analog-to-Digital and Digital-to-Analog) to handle signal conversion between these two formats (analog and digital formats).
- Memory: Most likely it is non-volatile memory which still retains all information even when the power is down or battery is removed from the device.
I hope this information can stimulate your thinking of what is the basic of electronic engineering is about in such product domain. :)