Definition
A load balancer is a device or software that distributes network traffic across multiple servers. It acts as a traffic manager, directing incoming requests to available servers to prevent any single server from becoming overwhelmed. This distribution ensures high availability and reliability for applications and services by preventing bottlenecks and downtime. For instance, a popular e-commerce website uses a load balancer to handle thousands of concurrent customer requests, ensuring smooth browsing and purchasing experiences. Load balancers are distinct from simple network routers as they actively monitor server health and intelligently route traffic based on server load and performance. Understanding load balancing is crucial for IT professionals and appears on certifications like CompTIA Security+, CISSP, and CCSP.