What is availability zone in AWS ?

What is availability zone in AWS ?

The number of Availability Zones (AZs) in Amazon Web Services (AWS) is not something that users can create or define; rather, they are predefined and managed by AWS itself. Each AWS Region consists of multiple, isolated, and physically separate AZs within a geographic area. The exact number of AZs varies from one AWS Region to another.

Here are some key points about AWS Availability Zones:

-Fixed Number per Region: AWS determines the number of AZs in each region based on various factors like demand, capacity, and geographical spread.

-Variable Across Regions: Some regions may have as few as two AZs, while others have more. Larger regions, especially those with high demand, tend to have more AZs.

-Continual Expansion: AWS has been continuously expanding its global infrastructure, adding new Regions and AZs. The number and distribution of AZs are subject to change as AWS grows.

-Purpose of AZs: Each AZ is designed to be isolated from failures in other AZs, offering redundancy and fault tolerance for hosted services and applications.

-Usage by Customers: Customers cannot create new AZs, but they can choose in which AZs to deploy their resources, such as EC2 instances or RDS databases, to achieve desired levels of availability and fault tolerance.