ALB (Application Load Balancer): Layer 7 (HTTP/HTTPS) traffic. It is "smart"—it can look at the actual website URL (e.g., /api vs /images) and route traffic to different servers accordingly.
NLB (Network Load Balancer): Layer 4 (TCP/UDP) traffic. It is "fast"—designed for millions of requests per second and ultra-low latency. It doesn't care about the content, just the packets.
CLB (Classic Load Balancer): The legacy generation. You generally shouldn't use this anymore unless you have very old requirements.
