Describe the difference between mechanical and electromagnetic waves. Give an example of each kind of wave related to telecommunications.

The main difference between mechanical and electromagnetic waves is that mechanical waves require a medium in order to propagate, while electromagnetic waves can propagate also in vacuum.

Examples of telecommunication via mechanical waves are sound waves (so, two people speaking to each other, for instance), while examples of telecommunication via electromagnetic waves are the radio waves that transmit the TV signals to the houses.