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A telegraph is a system for transmitting messages from a distance along a wire, especially one creating signals by making and breaking an electrical connection. -
A computer is an electronic device for storing and processing data, typically in binary form, according to instructions given to it in a variable program. -
The telephone is a telecommunication invention created to transmit aocustic signals at a distance by means of electrical signals. -
A radio is a telecommunication advice that is based on sending audio signals over radio waves, although the term is also used for other forms of remote audio transmission such as Internet radio. -
Television ia a transmition system that projects pictures, videos and audios by hertzian waves. -
A mobile phone is a portatil device that is used to recive calls and call other people. -
A tablet is a portatil device that has similiar uses to a mobile phone, even though it has a bigger size