Elastic Load Balancing automatically distributes your incoming traffic across multiple targets, such as EC2 instances, containers, and IP addresses, in one or more Availability Zones. It monitors the health of its registered targets, and routes traffic only to the healthy targets
Elastic Load Balancing supports the following load balancers: Application Load Balancers, Network Load Balancers, Gateway Load Balancers, and Classic Load Balancers.
The load balancer distributes incoming application traffic across multiple targets, such as EC2 instances, in multiple Availability Zones. This increases the availability of your application.
Sources: https://aws.amazon.com/blogs/networking-and-content-delivery/using-load-balancer-target-group-health-thresholds-to-improve-availability/
https://docs.aws.amazon.com/elasticloadbalancing/