This document discusses primary input and output devices used in computing. It defines input devices as any hardware used to provide data and control signals to a computer, such as keyboards, mice, webcams, and scanners. Output devices receive and display output from the computer, including monitors, printers, projectors, and speakers. The document also covers resolution, measured in pixels or dots per inch (dpi) for printers, and different types of impact printers like dot matrix and line printers versus non-impact printers like inkjet and laser printers.