The purpose of a load balancer in server management is to distribute incoming network traffic across multiple servers to ensure optimal performance and availability. By efficiently managing resource allocation, a load balancer helps prevent any single server from becoming overwhelmed, which can lead to downtime and slow response times. Load balancers can operate at various layers of the network stack and are essential in high-traffic situations to enhance reliability and scalability. They also improve user experience by reducing latency and ensuring continuous access to services.