The Peripheral Glossary: Every Computer Accessory Term, Defined

Why Peripheral Terminology Matters

Shopping for a monitor arm, reading a laptop spec sheet, or trying to figure out why your USB drive won't connect — in each case, the right vocabulary saves time and prevents costly mistakes. The word peripheral refers to any device that connects to a computer but isn't the computer itself. Peripherals expand what your machine can do: they add input, output, storage, or connectivity.

This glossary covers the terms that appear most often when you're researching or setting up a computer workspace. For a deeper look at how cables and ports fit together, see our guide to ports, hubs, and docks.

Display and Monitor Terms

Monitors are among the most impactful peripherals you can add to any workspace. Understanding their specs helps you evaluate what you're actually getting.

• Resolution — The number of pixels displayed, expressed as width × height (e.g., 1920×1080). Higher resolution means sharper images, but also demands more from your computer's graphics hardware.
• Refresh rate — How many times per second the screen redraws its image, measured in hertz (Hz). A 60 Hz display redraws 60 times per second; 144 Hz is common for smoother motion.
• Panel type — The underlying display technology. IPS panels offer wide viewing angles and accurate color; TN panels are faster and less expensive; OLED panels produce deeper blacks and higher contrast.
• Aspect ratio — The proportional relationship between a screen's width and height. 16:9 is the standard widescreen ratio; ultrawide monitors often use 21:9.
• Monitor arm — A adjustable mount that attaches a monitor to a desk or wall, freeing up surface space and improving ergonomic positioning. See how monitor arms improve comfort for more.

Connectivity Accessories: Hubs, Docks, and Dongles

Connectivity accessories bridge the gap between your computer's available ports and the devices you want to use. These three terms are often confused.

• USB hub — A device that expands one USB port into several, allowing multiple accessories to connect simultaneously. Hubs are typically bus-powered (drawing power from the computer) or self-powered (using their own adapter).
• Docking station (dock) — A more comprehensive hub that typically adds video outputs, ethernet, audio, and multiple USB ports through a single cable connection. Docks are common with laptops used at a desk.
• Dongle — A small adapter that converts one port type to another (e.g., USB-C to HDMI, or USB-A to USB-C). The term is informal but widely used.
• KVM switch — Short for Keyboard-Video-Mouse switch. A device that lets one set of input peripherals control multiple computers.

For a full breakdown of port types — USB-A, USB-C, Thunderbolt, HDMI — visit our ports and docks explainer.

Input Device and Storage Terms

Input devices are peripherals you use to send information to your computer. Storage peripherals hold data that moves between devices or provides backup.

• Mechanical keyboard — A keyboard using individual physical switches under each key, valued for tactile feedback and durability.
• Membrane keyboard — A keyboard using a pressure-sensitive layer beneath the keys, generally quieter and less expensive than mechanical designs.
• DPI (dots per inch) — A measure of mouse sensitivity. Higher DPI means the cursor moves farther per inch of physical mouse movement.
• External SSD — A solid-state drive in a portable enclosure. Faster and more durable than older spinning hard drives, used for file transfers and backup storage.
• NAS (Network Attached Storage) — A storage device connected to a home network rather than directly to one computer, making files accessible to multiple devices. This is distinct from cloud storage, which is managed by an outside service provider.
• Webcam — A standalone camera peripheral designed for video calls and conferencing, as opposed to the integrated camera in a laptop lid.

Readers interested in smartphone and tablet accessories will find parallel glossary concepts in our mobile camera glossary.