Serverless Developer Guide
Amazon has many regions all across the globe. Inside each region, there are one or more 
Availability Zones located tens of miles apart. The distance is near enough for low latency — 
the gap between requesting and receiving a response, and far enough to reduce the chance that 
multiple zones are aﬀected if a disaster happens.
Each region is identiﬁed by a code, such as "us-west-1", "us-east-1" or "eu-west-2". Within each 
region, the multiple isolated locations known as Availability Zones or AZs are identiﬁed with the 
region code followed by a letter identiﬁer. For example, us-east-1a. AWS handles deploying to 
multiple availability zones within a region for resilience.
Amazon Resource Name (ARN)
Services are identiﬁed with regional endpoints. The general syntax of a regional endpoint is as 
follows:
protocol://<service-code>.<region-code>.amazonaws.com
For example, https://dynamodb.us-west-1.amazonaws.com is the endpoint for the Amazon 
DynamoDB service in the US West (N. California) Region.
The region code is also used to identify AWS resources with Amazon Resource Names, also called 
"ARNs". Because AWS is deployed all over the world, ARNs function like an addressing system to 
precisely locate which speciﬁc part of AWS we are referring to. ARNs have a hierarchical structure:
Amazon Resource Name (ARN) 14