AWS Global Infrastructure

AWS has built one of the largest and most resilient networks in the world. Understanding its geographic structure is fundamental to designing fault-tolerant architectures — and it's heavily tested in every AWS certification exam.

AWS Regions

A Region is a physical geographic area where AWS has clusters of data centres. As of 2026, AWS operates 30+ Regions worldwide, including:

• US East (N. Virginia) — us-east-1 — the oldest and largest region
• EU (Ireland) — eu-west-1
• Asia Pacific (Singapore) — ap-southeast-1
• Asia Pacific (Mumbai) — ap-south-1

Each region is completely independent. Resources in one region are isolated from another. To replicate data between regions, you do so explicitly.

How to Choose a Region

1. Data residency and compliance: Regulations (GDPR, data sovereignty laws) may require data to stay in a specific country.
2. Latency: Choose the region closest to your end users.
3. Service availability: Not all services are available in every region. New services launch in US East first.
4. Pricing: Prices vary slightly by region.

Availability Zones

Within each region are Availability Zones (AZs) — typically 3 per region (some have 2, some have 6). Each AZ is:

• One or more discrete, physically separate data centres
• Isolated from failures in other AZs (separate power, cooling, networking)
• Connected to other AZs in the same region via redundant, low-latency fibre

AZ names: us-east-1a, us-east-1b, us-east-1c. The letter suffix is randomised per AWS account, so us-east-1a for you may be a different physical AZ than us-east-1a for someone else.

Why AZs Matter

Deploying your application across multiple AZs is the primary way to achieve high availability in AWS. If one AZ suffers a power outage or hardware failure, your application continues running in the other AZs. Services like Elastic Load Balancing, RDS Multi-AZ, and EKS are designed to span AZs automatically.

Edge Locations

AWS has 400+ Edge Locations worldwide — smaller points of presence that are not full regions. They serve two primary purposes:

• Amazon CloudFront (CDN): Static content (images, JS, CSS) is cached at the edge closest to the user, reducing latency from hundreds of milliseconds to single-digit milliseconds.
• Amazon Route 53: DNS queries are answered from the nearest edge location for maximum speed.

Local Zones and Wavelength Zones

• Local Zones: AWS infrastructure placed in large metropolitan areas, enabling single-digit millisecond latency to nearby users. Example: Los Angeles Local Zone extends us-west-2.
• Wavelength Zones: Infrastructure embedded in telecom providers' 5G networks, for ultra-low latency mobile and IoT applications.

AWS Outposts

AWS Outposts brings AWS hardware to your own data centre. You get the same AWS APIs and services, but running on physical servers in your facility. Used when regulations require on-premises data processing.

Global vs Regional vs AZ-Scoped Services

Understanding this scope is essential for building resilient architectures. The next lesson explores EC2, Lambda, and AWS's core compute services.