A computer device, such as a CD-ROM drive or printer, that is not part of the essential computer, i.e., the memory and microprocessor. Peripheral devices can be external — such as a mouse, keyboard, printer, monitor, external Zip drive or scanner — or internal, such as a CD-ROM drive, CD-R drive or internal modem. Internal peripheral devices are often referred to as integrated peripherals.
input device –
Any machine that feeds data into a computer. For example, a keyboard is an input device, whereas a display monitor is an output device. Input devices other than the keyboard are sometimes called alternate input devices. Mice, trackballs, and light pens are all alternate input devices.
Output Devices –
Any machine capable of representing information from a computer. This includes display screens, printers, plotters, and synthesizers
storage device –
A device capable of storing data. The term usually refers to mass storage devices, such as disk and tape drives
– Abbreviation of cathode-ray tube, the technology used in most televisions and computer display screens. A CRT works by moving an electron beam back and forth across the back of the screen. Each time the beam makes a pass across the screen, it lights up phosphor dots on the inside of the glass tube, thereby illuminating the active portions of the screen. By drawing many such lines from the top to the bottom of the screen, it creates an entire screen full of images.