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The telegraph is a system for transmitting messages from a distance along a wire, especially one creating signals by making and breaking an electrical connection.
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A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be heard directly.
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A radio is a box filled with electronic components that catches radio waves sailing through the air and converts them back into sounds your ears can hear.
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Television is a telecommunication medium used for transmitting moving images in monochrome (black and white), or in color, and in two or three dimensions and sound.
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A computer is a machine that can be instructed to carry out sequences of arithmetic or logical operations automatically via computer programming.
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A tablet is a mobile device, typically with a mobile operating system and touchscreen display processing circuitry, and a rechargeable battery in a single, thin and flat package.
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A mobile phone is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area.
