Load Balancer

A load balancer is a device or software that distributes incoming network traffic across multiple servers to ensure no single server becomes overwhelmed.

It is important because it improves the availability, reliability, and performance of applications by evenly distributing the load, preventing server overload, and providing failover capabilities in case of server failures.

Load balancers are usually used when scaling up RESTful microservices, as their stateless nature, you can set up multiple copies of the same one behind a load balancer and let it distribute the load amongst all copies evenly.