What is the primary function of a load balancer in a network?

The primary function of a load balancer in a network is to distribute traffic across multiple servers. This ensures that no single server becomes overwhelmed with too much traffic, which can lead to performance degradation or even server failure. By effectively managing incoming requests and spreading them across several servers, a load balancer optimizes resource use, maximizes throughput, minimizes response time, and increases the reliability of applications.

Load balancers can function at various layers of the OSI model, including Layer 4 (Transport) and Layer 7 (Application), enabling them to manage traffic based on both IP address and application-level details. This functionality helps maintain a smooth user experience, especially for high-traffic websites and applications, and provides redundancy in case one of the servers fails, thereby enhancing overall system resilience.

This role is essential in modern web architectures, particularly in environments that demand high availability, such as e-commerce sites or online service providers.