The ELB service was initially started as a single solution that provided some layer 4 and layer 7 support. However, as the applications in the cloud evolved, so did the requirements of the users. Modern applications require us to implement load balancing solutions that can either fully understand the structure of the traffic on layer 7, or support extremely high performance on the network layer and let the application handle what the application knows best. At the time of writing, there are three types of load balancing that can meet various application requirements:
- Classic Load Balancer: With both layer 4 and some layer 7 load balancing features
- Application Load Balancer: A pure layer 7 load balancer
- Network Load Balancer: A pure layer 4 load balancer