peripheral
adjective
[ pəˈrɪf(ə)r(ə)l ]
• relating to or situated on the edge or periphery of something.
• "the peripheral areas of Europe"
• (of a device) able to be attached to and used with a computer, though not an integral part of it.
• "a peripheral control processor"
peripheral
noun
• a peripheral device.
• "printers and other peripherals"
