Most of the time a Load balancer is a reverse proxy but a reverse proxy is not necessary a load balancer. Reverse proxy takes a request from client and forward it to “a server” doesn’t care of the server is overloaded or down or not just forwards it. Load balancer stores state about each server behind it, how overloaded each server is, and what server is down, and smartly forward request to a server to balance the load across all the group. So a load balancer is a special case of a reverse proxy but smarter!