The second way is to do wireless is by induction, where one wire induces current to flow in another. The third way is radiation, where high frequency, rapidly moving waves get generated by electricity and radiate from a fixed point like an antenna. I want to cover induction just a bit more, to better let us understand the difference between this method and what we now know as true radio. The above is a simple bar magnet with its lines of force. Wrap some wire around it, connect the wire to a battery and you will have an electromagnetic field.
Communications often use complex words for simple subjects.
We can define radio as the transmission and reception of signals by means of high frequency electrical waves without a connecting wire. And as we noted before, true radio requires that a signal modulate a carrier wave. Early induction schemes operated at low frequencies and possessed no modulating signal. As I stated above induction was well known to telegraphy, since signals often jumped from one line to another. In this case the wires are not physically crossed with each other, rather, induction induces one signal to travel on the wire of a nearby line.