Effective for sites that deal with large amounts of traffic. The load balancer will ensure that the server can handle the load along with providing failover in the case that a server becomes unresponsive. The load balancer will receive traffic requests first and then forward it to one of multiple servers placed behind it. Load balancers use varying algorithms to decide which server is best to deal with the request. Example algos: round-robin (sends requests to each server in turn) and weighted (checks how many requests a server is currently handling and sends it to the least busy server). Load balancers also periodically check server health (called a health check) to ensure that they are running correctly. If a server does not respond then the load balancer stops sending traffic until the server responds properly (bad server, no traffic for you!).