Environmental Protection. Didymo (Didymosphenia geminata), also known as rock snot, is a non-native invasive microscopic algae (diatom) that can produce large amounts of stalk material to form thick brown mats on stream bottoms. Didymo threatens aquatic habitat, biodiversity and recreational opportunities.
peripheral device - (computer science) electronic equipment connected by cable to the CPU of a computer; disk drives and printers are important peripherals.
A peripheral device is any auxiliary device that connects to and works with the computer to either put information into it or get information out of it. Usually, the word peripheral is used to refer to a device external to the computer, like a scanner, but the devices physically located inside the computer are also technically peripherals too. Peripheral devices often aren't directly involved with a computer's main function, but that doesn't mean they aren't considered necessary components.