Input and output devices provide means of communication between computers and outer world

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Explanation:

This question seem incomplete as what's required was not stated.

To answer this question, I'll assume it's a fill-in-the-gap question

The definition given above describes computer peripherals.

Peripherals is one of the links between a computer user and the computer itself.

Through peripherals such as keyboards, mouse, light pen , one can send input into the computer.

In the same vein, one can get outputs through peripherals such as the computer monitor, speakers, printers, etc.