Teleprinter
A teleprinter is like a typewriter. It is an electro-mechanical machine. Two or more teleprinters are connected through wires. When you type a message on one teleprinter, it is automatically typed on the other teleprinter connected to it. Thus, a message is instantly delivered. The teleprinters are out of fashion now, mainly because of the quick and efficient internet.
Telephone
The telephone is one of the most wonderful inventions of the modern times. It was invented by Alexander Graham Bell in 1876. Its greatest advantage is that you can talk with another person in real time; this makes it the fastest means. This is the reason that it has become one of the commonest means of communication today. You can talk to a person stationed near or far. It is a very valuable means of two-way communication.
When a person speaks into a telephone, the sound waves of his voice enter the mouthpiece, which change into an electric current, which is then carried to the telephone of the person he is talking to. A telephone is connected through wires and cables
Mobile Phone the Wonder Machine:
The invention of the mobile phone has made the telephone an integral part of our day-to-day personal and publication life. A mobile phone can be carried anywhere. Besides talking, a mobile phone is also used for several other applications, such as for sending messages, videos, pictures etc. In modern mobile phones, one can access Internet send and receive emails, do banking transactions, find directions, hear music, watch films, and more. With its vast range of applications, the mobile phone has emerged as a true wonder machine..