A load balancer is used to evenly distribute the load of network traffic or computer resources across multiple servers, devices, or network paths. It offers several benefits and purposes:

1. Scalability: A load balancer can assist in scaling a system by distributing traffic over multiple servers. This allows more users to be served simultaneously and can improve the performance of the system. It efficiently distributes the load, increasing the system's capacity.

2. Reliability: By distributing traffic across multiple servers or devices, a load balancer can improve the availability and reliability of a system. If a server or device fails, the load balancer can redirect traffic to other available servers, reducing the impact of an outage and improving the user experience.

3. Resource optimization: A load balancer can ensure that available resources are used efficiently. It distributes traffic based on the load of each server, preventing overloading of a single server. This allows servers to be used optimally and can enhance performance and response times.

4. Failover support: A load balancer can also provide failover support. This means that if a server or device fails, traffic is automatically redirected to other available servers. This ensures continuity of service and allows users to be seamlessly transferred to a working server without interruption of service.

In short, a load balancer is a valuable tool to improve the performance, scalability, and reliability of systems. It evenly distributes traffic over multiple servers or devices, optimizes the use of resources, and provides failover support, delivering a stable and efficient service to users.