A service that automatically distributes incoming traffic across multiple targets (EC2, containers, IPs). Types: Application Load Balancer (HTTP/HTTPS, layer 7), Network Load Balancer (TCP/UDP, layer 4), and Gateway Load Balancer.
Fundamental for high availability on CLF-C02 and SAA-C03. ALB for web apps (path/host-based routing), NLB for extreme low-level performance. Question: route /api to one target group and /web to another → ALB with routing rules.
Elastic Load Balancing (ELB) is a concept that can show up on the exam. Check the full guide to see it in context.