What is a computer keyboard
A computer keyboard is an input device designed to enter text. The text could include: numbers, letters, punctuation, special characters, special functions. A computer keyboard could be wired or wireless.
What is the keyboard used for
The keyboard is used to communicate to a computer like a translator. A computer doesn't understand our language only electric pulses or binary. Binary consists of ones and zeros or on and off in terms of a switch this is how the keyboard sends messages to the computer. Every character has a specific set of ones and zeros with it for example: a capital A is 01000001 but a lower case a is 01100001 see how there is a difference in ones and zeros.
How does it work
A keyboard is an input device it has it's own processor and circuitry this is called the key matrix. The key matrix is mostly made up of circuitry which is underneath the keys unless it's the capacitive models which will be mentioned later. A keyboard is an input device because it gives instructions to the computer.