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Internet Speed Glossary

Plain-language definitions of every term you will encounter in a speed test or internet plan. Click any term for the full explanation, with examples, FAQs, and related guides.

Speed Metrics

Mbps, Gbps, download, upload, throughput, bandwidth — the numbers that define your connection.

Latency & Quality

Ping, jitter, and latency — the terms that matter most for gaming, video calls, and real-time apps.

Connection Types

DSL, VDSL, fiber, broadband — understand what type of internet you have and how it compares.

Hardware

Modem, router, Wi-Fi, ISP — the equipment and providers that sit between you and the internet.

All Terms (18)

Bandwidth The maximum rate at which data can be transmitted over a network connection, measured in Mbps or Gbps. Broadband A high-speed internet connection that provides always-on access. The FCC defines broadband as at least 25 Mbps download and 3 Mbps upload. Download Speed The rate at which data travels from the internet to your device, measured in megabits per second (Mbps). DSL Digital Subscriber Line. A technology that delivers internet service over existing copper telephone lines. Fiber / FTTH Fiber to the Home. A broadband architecture where fiber-optic cable runs directly from the ISP to the customer premises. Gbps Gigabits per second. One Gbps equals 1,000 Mbps. Common for fiber internet plans. ISP Internet Service Provider. A company that sells internet access to homes and businesses. Jitter The variation in latency over time. High jitter causes choppy audio and video during calls. Latency The time it takes for a data packet to travel from your device to a server and back, measured in milliseconds. Mbps Megabits per second. The standard unit for measuring internet speed. 8 Mbps equals roughly 1 MB/s of file transfer. Modem A device that connects your home network to your ISP by converting signals between the two systems. NDT7 Network Diagnostic Tool version 7. The open-source protocol used by M-Lab to measure internet speed without ISP bias. Ping The round-trip time for a small data packet to travel from your device to a server and back, measured in milliseconds. Router A device that routes network traffic between your local devices and the internet. Throughput The actual rate at which data is successfully transferred. Throughput is what speed tests measure, as opposed to theoretical bandwidth. Upload Speed The rate at which data travels from your device to the internet. Important for video calls, sending files, and live streaming. VDSL Very High-Speed Digital Subscriber Line. A faster DSL variant that operates over shorter copper distances, delivering 50 to 100+ Mbps. Wi-Fi Wireless networking that lets devices connect to a local network without cables. Speed is affected by distance, interference, and the Wi-Fi standard.

Why Internet Speed Terms Are Confusing

ISPs, router manufacturers, and operating systems all use the same words to mean slightly different things. A plan advertised at "100 Mbps" will show roughly 12 MB/s in your download manager. Your speed test reports in Mbps while your file transfer shows MB/s. Your router's spec sheet quotes 867 Mbps but your device gets 200 Mbps. None of these are lies — they are just different units and measurement methods.

This glossary cuts through that confusion. Each entry explains the term in plain English, shows how it relates to real-world usage, and links to the relevant guides where you can go deeper.

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