What device balances the load among multiple web servers to increase performance?

A load balancer is a device specifically designed to distribute incoming network traffic across multiple servers. By doing so, it ensures that no single server becomes overwhelmed with too much traffic, which can lead to slower response times or even service outages. The primary purpose of a load balancer is to enhance application performance and reliability by efficiently managing workloads.

In addition to balancing the traffic load, a load balancer can also perform health checks on the backend servers, ensuring that requests are only directed to servers that are operational. This redundancy can significantly improve the overall availability of applications, making them resilient to server failures.

Other devices mentioned, such as routers, switches, and firewalls, serve different functions within a network. Routers are primarily responsible for directing traffic between different networks, switches connect devices within the same local area network, and firewalls are used to protect networks by monitoring and controlling incoming and outgoing network traffic based on security rules. While all these devices contribute to network performance in various ways, they do not specifically perform the function of distributing loads among servers like a load balancer does.