3.2 Define the AWS global infrastructure

The AWS Cloud operates 80 Availability Zones within 25 geographic Regions around the world, with announced plans for 9 more Availability Zones and 3 more Regions in Cape Town, Jakarta, and Milan.

AWS Regions and Availability Zones
The AWS Cloud infrastructure is built around Regions and Availability Zones (AZs). A Region is a physical location in the world with multiple AZs. Availability Zones consist of one or more discrete data centers, each with redundant power and networking, housed in separate facilities that are located on stable flood plains. These AZs offer the abilities to operate production applications and databases which are highly available, fault tolerant, and scalable than would be possible from a single data center. In total, the AWS Cloud operates 80 Availability Zones within 25 geographic Regions around the world.

Region & Number of Availability Zones
US East

N. Virginia (6), Ohio (3)

US West

N. California (3), Oregon (3)

Asia Pacific

Mumbai (2), Seoul (2), Singapore (2), Sydney (3), Tokyo (4), Bahrain

Canada

Central (2)

China

Beijing (2)

Europe

Frankfurt (3), Ireland (3), London (2)

South America

São Paulo (3)

AWS GovCloud (US-West) (2)

The components are:
 * Availability Zones (AZs)
 * Regions
 * Edge Locations
 * Regional Edge Caches

High Availability Through Multiple Availability Zones
Unlike virtually every other technology infrastructure provider, each AWS Region has multiple Availability Zones and data centers. As we’ve learned from running the leading cloud infrastructure technology platform since 2006, customers who care about the availability and performance of their applications want to deploy these applications across multiple Availability Zones in the same region for fault tolerance and low latency. Availability Zones are connected to each other with fast and private fiber-optic network, which enables applications to automatically fail-over between Availability Zones without interruption.

Further Improving Availability by Deploying in Multiple Regions
In addition to replicating applications and data across multiple data centers in the same Region using Availability Zones, you can also choose to further increase redundancy and fault tolerance by replicating data between geographic Regions. You can do so using both private and public network to provide an additional layer of business continuity, or to provide low latency access across the globe.

Meeting Compliance and Data Residency Requirements
You retain complete control and ownership over the region in which your data is physically located, making it easy to meet regional compliance and data residency requirements.

Geographic Expansion
The AWS Cloud has announced plans to expand with 9 more Availability Zones and 3 more Regions in Cape Town, Jakarta, and Milan.

Edge Locations
Edge Locations are AWS sites deployed in major cities and highly populated areas across the globe. They far outnumber the number of availability zones available.

While Edge Locations are not used to deploy your main infrastructures such as EC2 instances, EBS storage, VPCs, or RDS resources like AZs, they are used by AWS services such as AWS CloudFront and AWS Lambda@Edge (currently in Preview) to cache data and reduce latency for end user access by using the Edge Locations as a global Content Delivery Network (CDN).

As a result, Edge Locations are primarily used by end users who are accessing and using your services.

For example, you may have your website hosted on EC2 instances and S3 (your origin) within the Ohio region with a configured CloudFront distribution associated. When a user accesses your website from Europe, they would be re-directed to their closest Edge Location (in Europe) where cached data could be read on your website, significantly reducing latency.