Azure Regions and Availability Zones
Azure resources are deployed in locations around the world. Understanding regions and availability zones helps you choose where a workload runs and how it can handle local failures.
- What an Azure region is
- What an availability zone is
- The difference between zonal and zone-redundant resources
- What to check before choosing a region
What is an Azure region?
An Azure region is a set of physical facilities that contains datacenters and network infrastructure. A region consists of one or more datacenters connected by a high-capacity, fault-tolerant, low-latency network.
Examples of region names include West Europe, North Europe, Brazil South, and East US.
Not every Azure service is available in every region. Prices, features, quotas, and availability-zone support can also differ by region.
What is an availability zone?
An availability zone is a logical group of one or more physically separate datacenters inside an Azure region. Zones have independent power, cooling, and networking infrastructure.
The goal is fault isolation. If one zone has a local problem, resources in another zone can continue working when the workload and service are designed for that model.
Availability zones improve resilience to a zone failure. They do not replace backups, application-level resiliency, monitoring, or a disaster recovery plan for a complete regional outage.
Zonal and zone-redundant resources
Azure services can use availability zones in different ways.
You select a specific zone, such as Zone 1. The resource runs in that zone. You design the workload across multiple zones when needed.
The service distributes or replicates the resource across multiple zones. Azure manages the placement for that service.
The available option depends on the Azure service, region, tier, and configuration. Always check the service-specific reliability documentation.
How to choose a region
Do not choose a region only because it is the first item in a list. Check the requirements of the workload.
Also review pricing, quota availability, network connectivity, dependencies, and the organization’s support model.
A simple example
A web application needs high availability inside one region. The design can place application instances in more than one availability zone and use a service that can distribute traffic between healthy instances.
A second copy or recovery environment in another region may still be needed when the business requires protection from a full regional outage.
Check support before deployment
Before creating a resource:
- Open the official Azure regions list.
- Confirm the required service is available in the region.
- Confirm whether the service supports availability zones there.
- Check whether support is zonal, zone-redundant, or unavailable.
- Review the service’s reliability guide and limitations.
Summary
An Azure region is a physical deployment location made of datacenters and networking infrastructure. Availability zones are physically separate datacenter groups inside supported regions.
Regions answer where a resource is deployed. Availability zones help define how a workload can remain available during a local datacenter or zone failure.