Definition
Elastic Load Balancing, or ELB, is a service that automatically distributes incoming application traffic across multiple targets, such as Amazon EC2 instances, containers, and IP addresses. It acts as a single point of contact for clients, forwarding requests to healthy instances based on configured rules. This ensures high availability and fault tolerance by preventing any single instance from becoming overwhelmed or failing. For example, a popular e-commerce website uses ELB to handle fluctuating customer traffic during holiday sales, ensuring a smooth user experience. Unlike a single server, ELB dynamically scales its capacity to match traffic demands, preventing bottlenecks. This concept is fundamental for cloud architecture and appears on AWS certification exams like the Solutions Architect Associate.