Amazon AWS Concepts
Internal
Region
AWS has data centers in different areas of the world.
Amazon regions are: Asia Pacific (Tokyo) ap-northeast-1, Asia Pacific (Singapore) ap-southeast-1, Asia Pacific (Sydney) ap-southeast-2, EU (Frankfurt) eu-central-1, EU (Ireland) eu-west-1, South America (Sao Paulo) sa-east-1, US East (N. Virginia) us-east-1, US West (N. California) us-west-1, US West (Oregon) us-west-2.
Availability Zones
An availability zone is a distinct location within a region engineered to be isolated from failures in other availability zones. Think about it as location: by placing resources in different availability zones you can protect the application from the failure of a single location. Each region provides low-latency network connectivity with other zones within the same region. Example of availability zones within a region: us-west-2b.
The list of zones and their codes is available here:
Availability zone operations:
How to find the availability zone: Execute Template:Ec2-describe-instances, the availability zone is listed as an INSTANCE field.