It also acts as a wireless access point (WAP). Connect it to the internet using a cable, wirelessly, or in conjunction with a 3G or 4G dongle and it can share the connection with up to 8 computers.
The QG-103N also acts a power bank that can be used to charge a mobile phone or other device. It includes sophisticated circuitry to prevent overcharging and other risks.
It works as a backup device. For instance, it can be used to backup contacts from an Android or iOS device. It can also be used for backing up photographs. This is quite useful for people who, for example, use their iPhone on holiday rather than take a separate digital camera.
It is also a portable multimedia device. QNAP envisage multiple people using it within a car, each playing their own music or sending music to the car's audio system via Bluetooth.
Finally, by using a USB cable it can be used as a portable USB drive with a computer.
When it launched a few months back, the QG-103N sold for £100. However, it is now available for less than £50, suggesting perhaps that sales are not vigorous. The reaction of some people seems to be; "It's great! I want one! Er, what do I use it for...?"