Global Infrastructure: Regions & AZs

AWS runs data centers all over the world, organized into Regions and Availability Zones for low latency and high resilience.

AWS operates physical data centers across the globe. Understanding how they are organized helps you build applications that are fast and fault-tolerant.

Regions

A Region is a geographic area, such as us-east-1 (N. Virginia) or eu-west-1 (Ireland). You choose a Region based on where your users are, data-residency laws and price. Regions are isolated from one another.

Availability Zones

Each Region contains multiple Availability Zones (AZs) — one or more discrete data centers with independent power and networking, connected by fast private links. Spreading your app across AZs means a single data-center failure will not take you offline.

An AWS Region containing three isolated Availability ZonesAWS Region — us-east-1Availability Zone AData center 1Data center 2Availability Zone BData center 1Data center 2Availability Zone CData center 1Data center 2
A single Region contains multiple isolated Availability Zones.

Edge Locations

AWS also runs hundreds of Edge Locations used by CloudFront (the CDN) to cache content close to users for faster delivery.

Example

Example · bash
# List all AWS Regions available to your account
aws ec2 describe-regions --query "Regions[].RegionName" --output table

# List the Availability Zones inside your current Region
aws ec2 describe-availability-zones --query "AvailabilityZones[].ZoneName"

When to use it

  • A video streaming service deploys in eu-west-1 to minimize latency for European users while keeping US traffic in us-east-1.
  • A financial application spreads database replicas across three Availability Zones to survive a data-center failure without downtime.
  • A company uses AWS Local Zones to run latency-sensitive rendering workloads close to a major city not covered by the nearest full Region.

More examples

List All AWS Regions

Lists all AWS Regions including opt-in ones, showing the global spread of AWS infrastructure.

Example · bash
aws ec2 describe-regions \
  --all-regions \
  --query 'Regions[].{Region:RegionName,Endpoint:Endpoint}' \
  --output table

List Availability Zones in Region

Shows the Availability Zones within us-east-1, which are isolated data centers you spread workloads across for resilience.

Example · bash
aws ec2 describe-availability-zones \
  --region us-east-1 \
  --query 'AvailabilityZones[].{AZ:ZoneName,State:State}' \
  --output table

Create Subnets Across Two AZs

Creates subnets in two different AZs within the same Region, enabling high-availability application deployments.

Example · bash
aws ec2 create-subnet \
  --vpc-id vpc-0abc123 \
  --cidr-block 10.0.1.0/24 \
  --availability-zone us-east-1a

aws ec2 create-subnet \
  --vpc-id vpc-0abc123 \
  --cidr-block 10.0.2.0/24 \
  --availability-zone us-east-1b

Related

aws introaws vpc

Discussion

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