The vast majority of smaller electrical appliances sold internationally often have an external power supply (PSU) / power adapter, as different power supplies can then easily be attached depending on where in the world the appliance is sold; instead of building an advanced model into the device.
Alm. external power adapters often have a magical ability to get lost or break, and new original power adapters tend to be quite expensive. But a universal power supply does the job in the vast majority of cases and is much cheaper, and is often available with boats with different variable voltages (Volts), power output (Watts) and plug connections.
You can also choose a fixed power supply from 230V AC to, for example, a fixed 5 Volt DC direct voltage, often an advantage if it is important not to be able to change the voltage, and you just can find one that fits the device. 5V, 12V and 24V are the most common voltages, so you just have to make sure that there is enough power (Watt) and the plugs also fit.