The ELB service works by receiving traffic from different sources over the internet on a so-called listener. The listener is configured when you're creating an ELB, and it will define what type of traffic on which port the ELB will listen on. Any listener that we configure will also be associated with a single target group. If we are working with the ALB, we can also map multiple target groups to one listener, but we will need to define the listener rules so that the load balancer can determine how to send the traffic to the backend.
Once the correct target group is determined, the traffic is sent to one of the targets (instances, containers, on-premises, or external IP addresses) in the target group. All of the instances in a target group should be serving the same content so that when a client requests a certain page, file, and image, that content is...
