# availability zone

CEFR C1 · Compound

Source: https://englishreference.com/word/availability-zone
Updated: 2026-07-22

## Definition

a separate data center or group of data centers in a specific area. Companies use them to keep their websites running even if one center has a power cut or a problem.

For teachers: an isolated location within a data center region designed to be independent of failures in other zones. Each zone has its own power, cooling, and networking to ensure high availability and fault tolerance for cloud services.

## Examples

- We host our website in more than one availability zone.
- To prevent a total system outage, the engineer distributed the database across three different availability zones within the same geographic region.
- Architecting for high availability requires deploying redundant resources across multiple availability zones, ensuring that a localized hardware failure or utility disruption does not result in service downtime for the end user.

## Usage notes

- Commonly used in cloud computing contexts (e.g., AWS, Azure, Google Cloud).

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.