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.
Peripherals are commonly divided into three kinds: input devices, output devices, and storage devices (which partake of the characteristics of the first two). An input device converts incoming data and instructions into a pattern of electrical signals in binary code that are comprehensible to a digital computer. An output device reverses the process, translating the digitized signals into a form intelligible to the user. At one time punched-card and paper-tape readers were extensively used for inputting, but these have now been supplanted by more efficient devices.