In a wired system, the control is connected to the motor by electric wires which transmit your commands to the motor. This is the conventional home automation solution. In this case, the control unit is fixed near the motor (beside the window, for instance, for a motorised roller shutter). In the radio system, the commands are transmitted by radio waves. There is no electric wiring between the motor and the control.
The control is mobile, and you can control your roller shutter within a radius of up to 20 metres, even through a wall. Installation is quicker too, and saves your walls from being damaged. This is the neat, simple home automation solution. Note: with Somfy, a wired system can always be upgraded to a radio installation.