A Network Load Balancer is a device or software that distributes incoming network traffic across multiple servers. This helps ensure that no single server becomes overwhelmed with too much traffic, which can lead to slow performance or downtime. By balancing the load, it enhances the reliability and availability of applications. Network Load Balancers operate at the transport layer of the OSI model, typically using protocols like TCP or UDP. They can also provide features such as health checks to monitor server performance and automatic failover to reroute traffic if a server goes down, ensuring continuous service delivery.