Classic load balancer is an old-school tool, still used in some companies.
The classic load balancer (CLB) uses the following principles:
1. One classic load balancer per region
2. All classic load balancers use a central metadata service to get their configuration and to check the health of their instances
3. classic load balancers are built into classic containers
4. classic load balancer does not automatically create classic services, classic services must be created manually. classic load balancer is only responsible for distributing incoming requests to classic services and tracking classic container instances in a region and informing users about the current classic load balancer health. classic load balancing does not offer service discovery through classic DNS, classic load balancers know about classic services by their metadata only