Which AWS service helps ensure high availability across multiple Availability Zones?

The AWS Elastic Load Balancer (ELB) is specifically designed to distribute incoming application traffic across multiple targets, such as Amazon EC2 instances, containers, and IP addresses, in one or more Availability Zones. This capability ensures that if one Availability Zone experiences an issue, the load balancer can redirect traffic to healthy resources in other Availability Zones, thus maintaining high availability for applications.

By automatically scaling and distributing incoming traffic, ELB can help prevent any single point of failure. It continuously monitors the health of the associated resources and can dynamically route traffic away from instances that are not performing optimally. This feature is crucial for applications that require a high uptime and can significantly improve fault tolerance.

Other services, while also useful in their respective contexts, do not directly provide the same level of availability management across multiple Availability Zones. For instance, AWS Lambda is a serverless compute service that can be highly available as it runs code inresponse to events but does not offer traffic distribution across Availability Zones on its own. AWS CloudFormation is a tool for infrastructure as code, enabling you to provision resources but does not manage or balance traffic. AWS Route 53 is a DNS service that can help direct traffic based on geo-location or health checks but does not provide the load