The wireless one speaks of a non-wired transmission, for example - a signal that is not transmitted via cable but via the air!
Alternatively referred to as cordless, best describes this technology that transmits information or electricity through the air electromagnetically, without wires.
This is also the case with wireless or Wi-Fi, for example! The advantage of wireless transmission is of course that no cable is needed! There is hardly any need to rip open the walls or lay the cables in the ground. Even a satellite antenna that many have is a wireless transmission of the TV signal.