What is a computer peripheral? A computer peripheral is defined as a product that is outside of the CPU box that can be considered non-essential to the basic functions of the computer. For example, a printer is a peripheral because a computer can run by itself without it. A keyboard, mouse, and monitor should not be considered as a peripheral because a computer can't function thus called a computer without them.
(Note: "peripheral" is easily mis-spelled as pheripheral, pearipheral, paripheral, periperal, perpheral, perihperal, periferal, etc.)