The computer and other communicating devices represent data in the form of signals. The signals transmit between communicating devices in the form of electromagnetic energy, and hence the signals are called electromagnetic signals. Electromagnetic signals are the combination of electric and magnetic fields that vibrates in relation to each other. The electromagnetic signals can travel through various transmission media. The transmission media is broadly classified into two categories that are guided and unguided media.
The basic difference between guided and unguided media is that in the guided media, the signal travels through a physical medium whereas, in unguided media, the signal travel through the air. There are some more differences between guided and unguided media which I have discussed with the help of comparison chart shown below.