Region and Availability Zone in AWS


In AWS, a region is a geographical location that contains at least two Availability Zones (AZs). Each region is completely independent and isolated from other regions, which allows AWS customers to achieve high availability and fault tolerance by replicating their applications across multiple regions.

Need of Region

  • High availability
  • Low Latency
  • Adhere to government regulations
    • Eg: Some countries may not want to save their citizens data to other regions

How to choose the right region?

  • Based on the users there are located
  • Based on the data located
  • Based on the regulatory and security compliance need

AWS services can be regional or global.

Availability Zone

What is the availability zone?

It is:

  • An isolated location inside Region or we can say the data center inside Region
  • Each AWS region has at least two Availability Zones

Need of Availability Zone

  • The main need of the Availability Zone is to increase the availability of applications in the same region.
  • Let’s say, some customers want to use the specific Region to store data. And if there is only one Data Center then there is a high chance of failure. Hence, making multiple availability zones increases the availability of the applications within the same Region.

In this case, we can have our application in the same Region with high availability.

Let’s take an example of the region called North Virginia

  • Region Code: us-east-1
  • Regio: US East (N. Virginia)
  • Availability Zones: 6
  • Availability Zones List:
    • us-east-1a
    • us-east-1b
    • us-east-1c
    • us-east-1d
    • us-east-1e
    • us-east-1f

With the above list N. Virginia Region has 6 availability zones and there are: us-east-1a to us-east-1f

The availability zones code is the name of the region code followed by the alphabet.

Similarly, let’s take an example of the US West  Oregon Region

  • Region Code: us-west-2
  • Regio: US West (Oregon)
  • Availability Zones:4 
  • Availability Zones List:
    • us-west-2a
    • us-west-2b
    • us-west-2c
    • us-west-2d

It also has the same pattern as we described for N. Virginia Region

To understand in detail you can visit the link below: