What does a load balancer do in AWS?

A load balancer in AWS functions primarily to distribute incoming application traffic across multiple targets, such as virtual servers (EC2 instances). This process helps to ensure that no single server becomes overwhelmed with too much traffic, which can lead to performance degradation or server failures. By evenly distributing the traffic, the load balancer enhances the availability and reliability of applications, ensuring that clients receive consistent and timely responses.

Additionally, load balancers play a crucial role in health monitoring of the targets they distribute traffic to. If a target becomes unhealthy, the load balancer can automatically reroute traffic to other healthy targets, maintaining the application's operation with minimal disruption. This capability is essential for scaling applications and managing varying traffic loads effectively.

While the other options depict important functions that relate to cloud services, they do not accurately represent the primary role of a load balancer within AWS. File storage is handled by services like Amazon S3 or EFS, application performance analysis is typically conducted using tools like Amazon CloudWatch, and DNS management is handled by services such as Amazon Route 53. Hence, the first option captures the essence of what a load balancer does in the AWS environment.