AWS offers several kinds of load balancers:
- Classic load balancer
- Application load balancer
- Network load balancer
We're going to focus on the application load balancer in this section. It's effectively an upgraded, second-generation version of the ELB service, and it offers a lot more functionality than the classic load balancer. HTTP/2 and WebSockets are supported natively, for example. The hourly rate also happens to be cheaper.
Application load balancers do not support layer-4 load balancing. For this kind of functionality, you'll need to use a classic load balancer.