# What is bandwidth?

Bandwidth describes a connection’s capacity to transfer data over time.

Website: https://zenshield.com/glossary/bandwidth

Canonical URL: https://zenshield.com/glossary/bandwidth

Page reviewed: 2026-09-09

Bandwidth describes a connection’s capacity to transfer data over time. It is commonly expressed in bits per second, such as megabits per second. Capacity is different from the amount of data included in a monthly plan and from the delay before a response arrives.

## A practical example

Consider an illustrative 50 Mbps connection shared by several tasks. A large download, a video call and background updates all compete for available capacity. That does not mean each task will receive the advertised maximum at every moment.

## What to check

Before comparing results, note what else is using the connection and whether you are measuring upload or download. Try your actual task as well as a speed test. If a call struggles while a large upload is running, pause an optional transfer you control and compare once. Keep that observation separate from claims about the VPN.

## What it does not tell you

Bandwidth, data allowance and latency answer different questions: how much can flow per second, how much is included over a period, and how long a response takes. Paying attention to the right measure can prevent unnecessary changes to a working connection.

Read the [technical reference](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) for the underlying definition. For a connection that is failing now, use the [troubleshooting guide](https://zenshield.com/help/connection-problems). To choose an app, follow the [VPN selection worksheet](https://zenshield.com/learn/choosing-a-vpn).

## Sources
- https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth