A communication system is nothing more than a system that facilitates transfer of information from a source to a destination. In the real world, at the most fundamental level, there are literally countless numbers and types of communication systems. The following are some wide ranging examples:

  1. Two people talking to each other
  2. A computer network
  3. Your brain telling your finger to move
  4. Depressing a brake pedal leading to a car braking

The first two examples are very obviously communication systems, but what about the other two examples. If you think about it, in example three, the brain has information that says, “I want that finger to move”, and so it sends the appropriate nerve signal down to the finger, the finger “interprets” the signal and moves accordingly. So, the body’s nervous system is in fact a communication system.

You may think that example four is even more of a stretch, but again if you think about it, there is a person driving who is sending information to the brake, telling it to brake, by depressing the brake pedal.

In this section, however, I will not be looking at such esoteric communication systems as the nervous system, or an automobile. I will be examining electronic communication systems. In electronic communication systems, the input information/data may be in any form, and the output information may be in any form, but in order to transfer that information it must be converted to electromagnetic energy and propagated through a medium in that form.