A load balancer is a tool that allows distributing HTTP requests (or other kinds of network requests) among several backend resources.
The main operation of a load balancer is to allow traffic to be directed to a single address to be distributed among several identical backend servers that can spread the load and achieve better throughput. Typically, the traffic will be distributed through round-robin, that is, sequentially across all of them:
First one worker, then the other, consecutively:
That's ...