A hardwired thermostat is powered by a 240v mains supply, a physical wire (3 core plus earth) Is used to trigger the appropriate output, to a wiring centre if one of many thermostats, or directly to the output if a single zone.
A wireless thermostat communicates to a receiver using radio frequency (RF) (either single channel or multi zone depending on the number of thermostats you have) meaning no need for wiring between the thermostat and manifold. Our RF thermostats cannot take a floor limitation probe so other steps are required to protect temperature sensitive floor finishes.