How SQS Resilience works?

1. How many availability zones SQS uses for replicating the messages?

→ Based on the SQS SAQ here [A]:Amazon SQS stores all message queues and messages within a single, highly-available AWS region with multiple redundant Availability Zones (AZs), so that no single computer, network, or AZ failure can make messages inaccessible. Information about how many AZs a particular queue will be replicated to or which are those is not available to view directly.

2. Replicating the messages to multiple availability zones is automatically activated or a manual process?

→ Automatic

3. How many regions SQS uses for replicating the messages?

→ Single region. SQS queues cannot be shared between different regions.

4. Replicating the messages to multiple regions is automatically activated or a manual process?

→ N/A

5. Where can I see the availability zones, replicate availability zones, regions, and replicate regions information related to SQS?

→ You cannot see this information on your end, about which AZ a particular queue is replicated to, and etc. However, if you generally want to look up AZs of a particular region, you can run the following CLI command (change regions as needed):
aws ec2 describe-availability-zones —region us-east-1