When you receive your radio-wave TV signal over the air using an antenna, the electro-magnetic wave is converted to electrical AC current that includes the same frequencies as the radio-wave. This antenna captures the radio (aka TV) electromagnetic wave via the Electric field strength part of the electromagnetic wave.
The Antenna is connected to your TV set via the transmission line which could either be twin-lead or coaxial cable. More modern implementations likely use coaxial cable. The electromagnetic signal derived from the actual RF wave captured by the antenna is now moving through the coaxial cable at slightly slower speed. The speed of the wave is usually around 90 percent or so of light-speed due to the dielectric losses in the cable (twin lead offers a faster speed due to less losses).
So, when the signal is in the transmission line, it is just like an Internet signal that comes over cable or phone line. It is a modulated AC (alternating current) signal. With all TV in the US today and many other places, this is a digital modulated signal rather than the old style analog signal -- however, the signal itself moving through the wire is an analog voltage changing signal.
The transmission side of the TV or radio signal is also an antenna. Thus, the electromagnetic wave travels through space (atmosphere) from transmission antenna to receiving antenna. But, the electronics on the transmitting side also uses transmission line (usually coaxial cables) to deliver the signal to the transmitting antenna.
Therefore, if you were to extend that transmitting transmission line to your home and connect directly to your receiving transmission line (probably reduce power as well) then you have a system very much like the Internet connected via wires and switches (aka Routers).
So, not that much difference between the Internet wires based signaling system and the use of space born electromagnetic waves.