A peripheral device is defined as a computer device, such as a keyboard or printer, that is not part of the essential computer (i.e., the memory and microprocessor). These auxiliary devices are intended to be connected to the computer and used in conjunction with it. Examples of external peripherals include mouse, keyboard, printer, monitor, external Zip drive or scanner, while internal peripherals include CD-ROM drive, CD-R drive or internal modem. Today's new devices, such as tablets, smartphones and wearable computing devices are considered peripherals as they can be connected and used on a computer system. The difference, however, is that these devices can run independently of the computer system.