An Application Load Balancer is a type of Elastic Load Balancer that operates at the application layer (layer 7) of the OSI model. It can distribute incoming traffic across multiple targets, such as Amazon EC2 instances, containers, IP addresses, and Lambda functions. It can also route requests based on the content of the request, such as the host name, path, or query parameters1.

The AWS Load Balancer Controller is a controller that helps you manage Elastic Load Balancers for your Kubernetes cluster. It can provision Application Load Balancers or Network Load Balancers when you create Kubernetes Ingress or Service resources2.

By using the AWS Load Balancer Controller to provision an Application Load Balancer for your Amazon EKS cluster, you can achieve the following benefits:

You can route incoming requests to the appropriate microservices based on the rules you define in your Ingress resource. For example, you can route requests with different host names or paths to different microservices that handle customers and orders2.

You can improve the performance and availability of your container applications by distributing the load across multiple targets and enabling health checks and automatic scaling1.

You can reduce the cost and complexity of managing your load balancers by using a single controller that integrates with Amazon EKS and Kubernetes. You do not need to manually create or configure load balancers or update them when your cluster changes2.