The Classic Load Balancer is the original, legacy load balancer from AWS, providing basic load balancing at both Layer 4 (TCP/SSL/TLS) and Layer 7 (HTTP/HTTPS), and is primarily recommended for applications that were built within the EC2-Classic network [citation:2][citation:9].
The Classic Load Balancer (CLB) is the original offering from AWS and provides basic load balancing across multiple EC2 instances. It operates at both the request level (Layer 7) and the connection level (Layer 4). The CLB is intended for applications that were built within the EC2-Classic network. For new applications in a VPC, AWS recommends using an Application Load Balancer (ALB) for HTTP/HTTPS traffic and a Network Load Balancer (NLB) for TCP/UDP traffic [citation:2][citation:9].