Azure region
What it is
An Azure region is a set of data centers deployed within a latency-defined perimeter, connected by a dedicated low-latency network. Each region is the unit of geography where resources live (e.g. eastus, westeurope, uksouth).
Why it exists
You deploy resources to a particular region to control latency (near your users) and compliance/residency (data stays where the law allows). A resource is always created in one region; a single subscription can hold resources in many regions.
Key ideas
- Region pair — most regions are paired with another region for disaster recovery (e.g. EastUS ↔ WestUS); paired regions are updated/serviced one at a time and provide cross-region replication.
- Latency domain — resources in the same region communicate over Azure’s backbone, not the public internet.
- Sovereign clouds — separate deployments like Azure Government or Azure China are physically isolated from the public regions.
- Geographies — a grouping of regions (e.g. Americas, Europe) that satisfies data-residency boundaries.
How it fits (diagram)
Diagrams courtesy of Microsoft Learn / Azure docs: reliability/availability-zones-overview
Exam notes
- A resource is created in exactly one region; you pick it at deploy time and it’s immutable afterwards.
- Region pairs are the AZ-104 DR concept: most regions have a designated pair.
- Not all services are in all regions — some are regional, some global, some multi-region.
Related
availability-zones · subscription · resource-group
📘 Source: Microsoft Learn — Azure Region