Load balancing is a group of techniques used to ensure that loads are spread between multiple systems. The term is used on networking and server environments, with similar results.
Network load balancing involves using multiple connections or links to spread speed or high demand between those connections. That can be done on backbone links, carrier internet links or even from servers to switches to provide more speed using link sharing.
Server load balancing utilizes hardware (hardware load balancers) or software (software load balancers) to spread the requests destined for a domain or system between various servers behind those load balancers (often named backends). Load balancing ensures that high performance and scalability can be achieved by addition of servers.