AWS Regions are the physical locations around the world where AWS data centers are located. They are designed to be completely isolated from each other to achieve the greatest possible fault tolerance and stability. Each region is a separate geographic area, and each region has multiple, isolated locations known as Availability Zones (AZs).
An availability zone is a data center or group of data centers that are located close enough to each other to provide low-latency network connectivity between them. However, they are far enough apart to significantly reduce the risk that a single event, such as a fire, flood, or power outage, could affect more than one Availability Zone. They are desinged to be independent of each other, with their own power, cooling, and networking. This is to ensure that if one Availability Zone goes down, the others will still be operational.
When deploying your applications on AWS using services such as AWS lambda, EC2, or S3, you can choose the AWS region that is closest to your customers to ensure low latency and high performance. You can also deploy your applications in multiple regions to ensure high availability and fault tolerance.
While choosing a region you should always try to optmize for latency, cost, and legal requirements. For each product, costs can vary by region, so you should always check the pricing page to see the costs for the region you are interested in.
Today, there are 33 regions around the world, and more than 100 Availability Zones in which you can run your AWS resources.
All currently available AWS regions are: