Telegraphy, a technology developed in the early 18th century, revolutionized long-distance communication. It was a simple electrical circuit that transmitted electric signals over a wire, between stations.
Through the telegraph lines, messages could be sent back and forth as bursts of electricity. It was the connection between electricity and magnetism that led to this path-breaking invention.
By the end of the 19th century, another invention surfaced – the telephone. It was a different and advanced device that improved 
communication between long distances. In a telephone, an electric current carries the sound. Here again, the invention followed the principle of electromagnetism.
Another important device that works on the same principle is the loudspeaker. It converts an electrical signal from devices like a radio, or television into sound. For this purpose, the signals have to be connected to an electronic amplifier.
Generally, a loudspeaker is built using a coil of thin copper wire, a still paper cone and a circular magnet. When electrical signals are passed through, the coil of copper wire moves back and forth. This, along with the magnet, causes the paper cone to vibrate and reproduce sounds.
Taking into consideration the above mentioned devices, as well as other equipment, one can say that no invention in recent times has been complete without electricity.